New Tires for Tow Vehicle

[ddbck]

Originally Posted by DottieM

They ARE a good tire because they're Toyo, but they ride rough! "Do I have shocks in this truck?" They also have minimum traction which could be an issue in less than perfect weather. Just something to think about.

Couldn't be further from the truth! The Big-O Bigfoot (load range E) ride is fantastic, traction is outstanding in the difficult & always changing Wyoming weather. I've had them on 3 different trucks & have towed many different trailers & campers. You don't know what your talking about.

[JimMorrell]

If your truck has a tow package, you will be just fine getting the same tires that came with it.

[old40ford]

Originally Posted by Triple S

You are correct. I had a typo I meant to type GCVWR.



You lost me here.

I'm actually looking at the Goodyear Trail Runner A/T- LT. I'll check on these too.

Has anybody had any experience or have knowledge on the following? If so what do you thing?

- Bridgestone Dueler AT (E-121S)
- Toyo Open Country H/T (E-121S)
- Goodyear Trail Runner A/T (E-121-S)
- BF Goodrich K02 (E-121-S)
- BF Commercial (E-121-R)
- YOKO Geolander H/T (E)
- YOKO A/T (E-121-S)

Thanks again for all of the responses. It is helping a lot.

I have the Yokohama A/T tires on my F-150, 10 ply, ride nice and i can't hear them. They are wearing very well, but, now they are about 5 years old and I can see a little bit of weather checking on them so I am looking at new ones soon I think.

[Triple S]

Thanks for the help. I did go with an "E" rated tire and purchased the Nitto Grappler G2. From what I found they hold up really good and drive good. I'll try to remember to post how they work after several trips. My last question is how do you do the chalk test. I want to make sure I have the pressures set right. The owners of the tire store, who both pull TT's, told me to have the PSI set at 60lbs on all 4 when not towing. When towing have the rears at 80.

[cstover]

Originally Posted by Triple S

Thanks for the help. I did go with an "E" rated tire and purchased the Nitto Grappler G2. From what I found they hold up really good and drive good. I'll try to remember to post how they work after several trips. My last question is how do you do the chalk test. I want to make sure I have the pressures set right. The owners of the tire store, who both pull TT's, told me to have the PSI set at 60lbs on all 4 when not towing. When towing have the rears at 80.

Good choice. That is what I run on my Dodge 3500 towing my 5th wheel.

[Viber]

I bought my first travel trailer this past week. It is a 2016 Vibe 250BHS that weighs approximately 4300 lbs. My tow vehicle is a 2009 Toyota Tundra Limited Crewmax. I am new to this website and I have read the posts regarding the best tires for tow vehicles but I am open to suggestions. I will be mounting the tires on 20" aftermarket rims. I am looking for stronger sidewalls. Any suggestions are greatly appreciated.

[Jakieboy]

Viber - If you are looking for tires for your Toyota Tundra I would recommend you take the time to research whether there are Michelin LT tires available in the proper size. I have used nothing but Michelin tires on the tow vehicles that I have owned for the past 40 years. Never had one problem or failure. They are available at COSTCO and at all America's Tire outlets.

[Viber]

Jakie-Boy - thanks for your advice. I have read reviews on so many tires gets a bit confusing.

[DottieM]

To Viber: I receive the Forest River Forums in my email and asked my husband to give an answer to your inquiry about tires, so the following was written by husband. He has over 50 years in the truck and tire industry. He sold lite and medium duty trucks for many of those years, and he was Service Manager in tire stores for many of those years. He is an ASE Certified Master Mechanic for lite and medium duty trucks. I know there are those who have done what you are asking about and will say they’ve had no problems, but my husband is trying to give you information so you can make an intelligent decision that may effect the safety of your family. Simply stated, “he knows of where he speaks”.
He says:
First off, let me say that short sidewall, wide tires and larger wheels look really, really, cool! And they work nice for quick steering response (on a pickup?) on my race car. I understand the desire to have them and I have a couple of vehicles that have that setup on them. So, I am not totally against the application, BUT, you will NOT find them on my tow rig.
In the tire industry we see many trends/problems. Certain vehicles wear out tires faster than others. Some wear out rear tires at alarming rates. (for many different reasons) Some wear out the inner sides of the treads even though the tires are aligned to factory specs, and the “MANY” problems that people have with ultra-low profile tires (18”-22”) equal 10 times the problems versus standard size tires. I am speaking of the tires that have aspect ratios below “60”.
Aspect ratio is the percentage of height to width of the tire. To keep it simple, the lower the aspect ratio the shorter the sidewall height. (60 being shorter than 70, 50 being shorter than 60) In the 1960s and 1970s we saw what was called (Firestone term) wide ovals. F70-14 or G60-15. Back then we thought that these were “wide” tires. We still use aspect ratios to describe tire design/profile (225/50R-16) today. The proven theory is that a lower aspect ratio (within reason) has lower rolling resistance for better fuel economy. (It has to do with the sidewall design: The bulge on the sidewall where the tire rests on the street. The least amount that the sidewall changes as it rolls. The lower the rolling resistance. Goodyear came out with the NCT tire back in the late 1970s. NCT stood for Neutral Contour Tire. In essence, the bulge is built/molded in. The shorter the sidewall, the easier to have a tire with less bulging sidewalls.) So, if you read our discussion in another post about tire pressures and load range, the more volume/pressure of air, the more weight carry capacity a tire has. So, putting a 35 series tire on a vehicle deceases the rolling resistance of the tire, but when that tire needs to carry 1,800 pounds of weight, the only way to accomplish that is to make a wider tire to accommodate the needed weight. Now, the lower rolling resistance goes out the window because now the tread width is 14” wide and the tire now weighs 50 lbs which negates any fuel savings because of the added weight, rolling resistance and horsepower/torque required to overcome the inertia of the heavier tires.
By now, you are realizing that a tire is a huge compromise when it comes to aspect ratio design for load capacity, fuel economy, ride comfort and tire wear. (The shorter the sidewall, the softer the suspension has to be to be able to control the suspension, so shocks and bushings need to be more precise) Just like a tire is a huge compromise when it comes to long tire wear versus good traction. (Long tire tread life is at one end of the scale and good traction is at the other end of the scale. The closer that you can get the too extremes to meet, the higher the price of the tire goes.)
Now to address your 20” tire question and trailer towing. I realize that you are not talking a huge amount of weight, so just about anything would be “ok” but never the best idea when it comes to 20” tire options. Remember, if the 20” tires came from the factory, then the suspension has to be softer to accommodate the lack of cushion effect that you would get from a taller sidewall. (Softer suspension for towing a trailer? Not for me, thank you.) And if not from the factory then you will get a harsher ride and a higher maintenance cost every time it comes time to replace the tires. And since we are talking about replacement, YOU WILL be replacing them more often. The tread of the tire is the part touching the road and that is where the heat is generated. The sidewall of the tire dissipates the heat. So let’s see, wider (more) tread and shorter (less) sidewall. This sounds like a recipe for shorter tire life. Especially with the added weight of a trailer. Also, damage is more likely to happen to a shorter sidewall tire. If you do city driving, then the likely event of curbing scrapping the wheels and sidewall damage is highly increased. Not to mention pothole damage to tire and wheel. Again, you have less sidewall to cushion the impact of the pot hole edge and more likely to pinch the sidewall of the tire between the edge of the pothole and the rim causing a sidewall failure. Tire retailers/wholesalers love short aspect ratio tires because they get to sell more! In addition to the cost aspect, there is the traction aspect. You will also have less traction per square inch (same weight spread out over a wider area) which is detrimental when driving in snow and wet conditions, not to mention uneven grass at campsites. (The same thing happens with a dual rear wheel truck versus a single rear wheel truck having the same weight when trying to plow snow. The single rear truck will win every time, even though the dually has more traction edges on the tires.) I have even seen diesel pusher motor homes with dual rear wheels be stuck on wet grass at the race track. A person living in rural areas will experience less traction on gravel and mud, and the occasional rock will have the same effect of curbing or potholes.
My advice is to select the narrowest/narrower tire that will fit your stock wheels (same outside diameter within a few 10ths of an inch) AND carry the same or more weight. That will probably require going up in load capacity. (Standard to Load range “C” or “D”). Why a narrower tire when we are talking load capacity? When pulling a trailer or hauling a heavy or tall load you are looking to increase the sidewall rigidity. You are going to be inflating to max “tire” inflation which will “stiffen” up the sidewalls on the rear tires and give you less flex and rolling at the shoulders. This will decrease the sidewall flex which causes a tire to weaken, keep the heat buildup to a minimum and increase stability. You will then run 15psi less in the front tires for maximum stability. (Imagine a tire that is wider than the wheel and then imagine a tire that is the same width as the wheel. Inflate both tires to the same pressure. Which sidewall is going to give you the maximum stability? The tire that is wider will have some “rolling around movement” until the sidewalls will stop (come to the end) of how far the wheel can travel from one side to the other. The tire that is the same width virtually has nowhere to go when side forces (sway) occurs.)
My buddy had a Toyota 4-Runner with factory 17” wide low aspect tires from the factory. Not only was the tread design not adequate for getting him up the hill to his cabin, the width of the tire made normal snow traction a disaster. (even being a AWD/4WD vehicle) Plus he towed a trailer on occasion. I was able to find a load range “E” tire that was the same outside diameter and had a max width of the wheels that Toyota came with. Please note!!!!!!! HE DID HAVE TO REVISE HIS TIRE PRESSURES TO MEET RIDE AND LOAD CAPCACITY REQUIREMENTS. I was concerned that the ride would be too stiff. (A pickup truck with a long wheelbase is one thing, but a short wheelbase/light weight SUV would be something else.) However, when researching the tire weights, (original tires versus the increased load range) the load range “E” tires were only 2 pounds heavier than the originals because of the narrower aspect. (The higher the un-sprung weight, the worse the ride. Example being a loaded and unloaded truck. You add to the load (sprung weight) and the percentage changes to give you a better ride.) The 4-Runner did have a slightly firmer ride but in no way objectionable, and the difference in climbing the hill to the cabin was amazing. Needless to say, when those tires were worn out he replaced them with the same ones.
I know that you probably did not want to hear what I have said, and I have probably told you more than you wanted to hear, (AND TOOK TOO LONG TO TELL IT!) but these are my guidelines for tow vehicle tires. As an aside note: my sister has a 1500 Chevrolet truck with 18” low aspect tires. She has a camp trailer that she tows. Have we changed the tires form the originals? No. Has she been told (and is now religious) about the tire pressures? Yes. Will she be going to the same tires when the originals wear out? Absolutely not! (in fact we have already changed the tires on her camper even though they were just a little over 2 years old because one failed big time) But because she has only a Forest River R-Pod, the stresses are not nearly the same as a trailer that is taller or heavier.
One more note. If you are at a tire store that does not comprehend what you are trying to do and why find someone else or another tire store. Or you may run across someone who tells you all this stuff does not matter. They are being lazy and do not care about your concerns, nor are they having to drive your rig loaded. (The most enjoyable trips are when you are not concerned about what may happen or when you do not have to keep fighting an ill-handling rig.) Most of the “name brand” tire companies have the schools to teach these things, so a “lesser brand” dealer may not have the proper training. Sometimes a tire dealer that specializes in light truck tires will do this type of research as a matter of daily operations.
Good luck with your RVing!

[Viber]

Hi DottieM. I am grateful and impressed by your very detailed response to my question. I have done some extensive research into the towing vehicle tires and I have spoken to a tire specialist that I was referred to by a friend. I have decided on the BF Goodrich KO2/A 20". I don't tow all the time and my truck is my weekend vehicle. I will let you know how it works out. The tire specialist has the same tires on his F150 and he is very satisfied with them. He strongly recommends tire rotations every 10000 km and to maintain proper air pressures.

[ddbck]

Originally Posted by DottieM

To Viber: I receive the Forest River Forums in my email and asked my husband to give an answer to your inquiry about tires, so the following was written by husband. He has over 50 years in the truck and tire industry. He sold lite and medium duty trucks for many of those years, and he was Service Manager in tire stores for many of those years. He is an ASE Certified Master Mechanic for lite and medium duty trucks. I know there are those who have done what you are asking about and will say they’ve had no problems, but my husband is trying to give you information so you can make an intelligent decision that may effect the safety of your family. Simply stated, “he knows of where he speaks”.
He says:
First off, let me say that short sidewall, wide tires and larger wheels look really, really, cool! And they work nice for quick steering response (on a pickup?) on my race car. I understand the desire to have them and I have a couple of vehicles that have that setup on them. So, I am not totally against the application, BUT, you will NOT find them on my tow rig.
In the tire industry we see many trends/problems. Certain vehicles wear out tires faster than others. Some wear out rear tires at alarming rates. (for many different reasons) Some wear out the inner sides of the treads even though the tires are aligned to factory specs, and the “MANY” problems that people have with ultra-low profile tires (18”-22”) equal 10 times the problems versus standard size tires. I am speaking of the tires that have aspect ratios below “60”.
Aspect ratio is the percentage of height to width of the tire. To keep it simple, the lower the aspect ratio the shorter the sidewall height. (60 being shorter than 70, 50 being shorter than 60) In the 1960s and 1970s we saw what was called (Firestone term) wide ovals. F70-14 or G60-15. Back then we thought that these were “wide” tires. We still use aspect ratios to describe tire design/profile (225/50R-16) today. The proven theory is that a lower aspect ratio (within reason) has lower rolling resistance for better fuel economy. (It has to do with the sidewall design: The bulge on the sidewall where the tire rests on the street. The least amount that the sidewall changes as it rolls. The lower the rolling resistance. Goodyear came out with the NCT tire back in the late 1970s. NCT stood for Neutral Contour Tire. In essence, the bulge is built/molded in. The shorter the sidewall, the easier to have a tire with less bulging sidewalls.) So, if you read our discussion in another post about tire pressures and load range, the more volume/pressure of air, the more weight carry capacity a tire has. So, putting a 35 series tire on a vehicle deceases the rolling resistance of the tire, but when that tire needs to carry 1,800 pounds of weight, the only way to accomplish that is to make a wider tire to accommodate the needed weight. Now, the lower rolling resistance goes out the window because now the tread width is 14” wide and the tire now weighs 50 lbs which negates any fuel savings because of the added weight, rolling resistance and horsepower/torque required to overcome the inertia of the heavier tires.
By now, you are realizing that a tire is a huge compromise when it comes to aspect ratio design for load capacity, fuel economy, ride comfort and tire wear. (The shorter the sidewall, the softer the suspension has to be to be able to control the suspension, so shocks and bushings need to be more precise) Just like a tire is a huge compromise when it comes to long tire wear versus good traction. (Long tire tread life is at one end of the scale and good traction is at the other end of the scale. The closer that you can get the too extremes to meet, the higher the price of the tire goes.)
Now to address your 20” tire question and trailer towing. I realize that you are not talking a huge amount of weight, so just about anything would be “ok” but never the best idea when it comes to 20” tire options. Remember, if the 20” tires came from the factory, then the suspension has to be softer to accommodate the lack of cushion effect that you would get from a taller sidewall. (Softer suspension for towing a trailer? Not for me, thank you.) And if not from the factory then you will get a harsher ride and a higher maintenance cost every time it comes time to replace the tires. And since we are talking about replacement, YOU WILL be replacing them more often. The tread of the tire is the part touching the road and that is where the heat is generated. The sidewall of the tire dissipates the heat. So let’s see, wider (more) tread and shorter (less) sidewall. This sounds like a recipe for shorter tire life. Especially with the added weight of a trailer. Also, damage is more likely to happen to a shorter sidewall tire. If you do city driving, then the likely event of curbing scrapping the wheels and sidewall damage is highly increased. Not to mention pothole damage to tire and wheel. Again, you have less sidewall to cushion the impact of the pot hole edge and more likely to pinch the sidewall of the tire between the edge of the pothole and the rim causing a sidewall failure. Tire retailers/wholesalers love short aspect ratio tires because they get to sell more! In addition to the cost aspect, there is the traction aspect. You will also have less traction per square inch (same weight spread out over a wider area) which is detrimental when driving in snow and wet conditions, not to mention uneven grass at campsites. (The same thing happens with a dual rear wheel truck versus a single rear wheel truck having the same weight when trying to plow snow. The single rear truck will win every time, even though the dually has more traction edges on the tires.) I have even seen diesel pusher motor homes with dual rear wheels be stuck on wet grass at the race track. A person living in rural areas will experience less traction on gravel and mud, and the occasional rock will have the same effect of curbing or potholes.
My advice is to select the narrowest/narrower tire that will fit your stock wheels (same outside diameter within a few 10ths of an inch) AND carry the same or more weight. That will probably require going up in load capacity. (Standard to Load range “C” or “D”). Why a narrower tire when we are talking load capacity? When pulling a trailer or hauling a heavy or tall load you are looking to increase the sidewall rigidity. You are going to be inflating to max “tire” inflation which will “stiffen” up the sidewalls on the rear tires and give you less flex and rolling at the shoulders. This will decrease the sidewall flex which causes a tire to weaken, keep the heat buildup to a minimum and increase stability. You will then run 15psi less in the front tires for maximum stability. (Imagine a tire that is wider than the wheel and then imagine a tire that is the same width as the wheel. Inflate both tires to the same pressure. Which sidewall is going to give you the maximum stability? The tire that is wider will have some “rolling around movement” until the sidewalls will stop (come to the end) of how far the wheel can travel from one side to the other. The tire that is the same width virtually has nowhere to go when side forces (sway) occurs.)
My buddy had a Toyota 4-Runner with factory 17” wide low aspect tires from the factory. Not only was the tread design not adequate for getting him up the hill to his cabin, the width of the tire made normal snow traction a disaster. (even being a AWD/4WD vehicle) Plus he towed a trailer on occasion. I was able to find a load range “E” tire that was the same outside diameter and had a max width of the wheels that Toyota came with. Please note!!!!!!! HE DID HAVE TO REVISE HIS TIRE PRESSURES TO MEET RIDE AND LOAD CAPCACITY REQUIREMENTS. I was concerned that the ride would be too stiff. (A pickup truck with a long wheelbase is one thing, but a short wheelbase/light weight SUV would be something else.) However, when researching the tire weights, (original tires versus the increased load range) the load range “E” tires were only 2 pounds heavier than the originals because of the narrower aspect. (The higher the un-sprung weight, the worse the ride. Example being a loaded and unloaded truck. You add to the load (sprung weight) and the percentage changes to give you a better ride.) The 4-Runner did have a slightly firmer ride but in no way objectionable, and the difference in climbing the hill to the cabin was amazing. Needless to say, when those tires were worn out he replaced them with the same ones.
I know that you probably did not want to hear what I have said, and I have probably told you more than you wanted to hear, (AND TOOK TOO LONG TO TELL IT!) but these are my guidelines for tow vehicle tires. As an aside note: my sister has a 1500 Chevrolet truck with 18” low aspect tires. She has a camp trailer that she tows. Have we changed the tires form the originals? No. Has she been told (and is now religious) about the tire pressures? Yes. Will she be going to the same tires when the originals wear out? Absolutely not! (in fact we have already changed the tires on her camper even though they were just a little over 2 years old because one failed big time) But because she has only a Forest River R-Pod, the stresses are not nearly the same as a trailer that is taller or heavier.
One more note. If you are at a tire store that does not comprehend what you are trying to do and why find someone else or another tire store. Or you may run across someone who tells you all this stuff does not matter. They are being lazy and do not care about your concerns, nor are they having to drive your rig loaded. (The most enjoyable trips are when you are not concerned about what may happen or when you do not have to keep fighting an ill-handling rig.) Most of the “name brand” tire companies have the schools to teach these things, so a “lesser brand” dealer may not have the proper training. Sometimes a tire dealer that specializes in light truck tires will do this type of research as a matter of daily operations.
Good luck with your RVing!

Isn't this basic common knowledge?

[GerryK]

Originally Posted by DottieM

To Viber: I receive the Forest River Forums in my email and asked my husband to give an answer to your inquiry about tires, so the following was written by husband. He has over 50 years in the truck and tire industry. He sold lite and medium duty trucks for many of those years, and he was Service Manager in tire stores for many of those years. He is an ASE Certified Master Mechanic for lite and medium duty trucks. I know there are those who have done what you are asking about and will say they’ve had no problems, but my husband is trying to give you information so you can make an intelligent decision that may effect the safety of your family. Simply stated, “he knows of where he speaks”.
He says:
First off, let me say that short sidewall, wide tires and larger wheels look really, really, cool! And they work nice for quick steering response (on a pickup?) on my race car. I understand the desire to have them and I have a couple of vehicles that have that setup on them. So, I am not totally against the application, BUT, you will NOT find them on my tow rig.
In the tire industry we see many trends/problems. Certain vehicles wear out tires faster than others. Some wear out rear tires at alarming rates. (for many different reasons) Some wear out the inner sides of the treads even though the tires are aligned to factory specs, and the “MANY” problems that people have with ultra-low profile tires (18”-22”) equal 10 times the problems versus standard size tires. I am speaking of the tires that have aspect ratios below “60”.
Aspect ratio is the percentage of height to width of the tire. To keep it simple, the lower the aspect ratio the shorter the sidewall height. (60 being shorter than 70, 50 being shorter than 60) In the 1960s and 1970s we saw what was called (Firestone term) wide ovals. F70-14 or G60-15. Back then we thought that these were “wide” tires. We still use aspect ratios to describe tire design/profile (225/50R-16) today. The proven theory is that a lower aspect ratio (within reason) has lower rolling resistance for better fuel economy. (It has to do with the sidewall design: The bulge on the sidewall where the tire rests on the street. The least amount that the sidewall changes as it rolls. The lower the rolling resistance. Goodyear came out with the NCT tire back in the late 1970s. NCT stood for Neutral Contour Tire. In essence, the bulge is built/molded in. The shorter the sidewall, the easier to have a tire with less bulging sidewalls.) So, if you read our discussion in another post about tire pressures and load range, the more volume/pressure of air, the more weight carry capacity a tire has. So, putting a 35 series tire on a vehicle deceases the rolling resistance of the tire, but when that tire needs to carry 1,800 pounds of weight, the only way to accomplish that is to make a wider tire to accommodate the needed weight. Now, the lower rolling resistance goes out the window because now the tread width is 14” wide and the tire now weighs 50 lbs which negates any fuel savings because of the added weight, rolling resistance and horsepower/torque required to overcome the inertia of the heavier tires.
By now, you are realizing that a tire is a huge compromise when it comes to aspect ratio design for load capacity, fuel economy, ride comfort and tire wear. (The shorter the sidewall, the softer the suspension has to be to be able to control the suspension, so shocks and bushings need to be more precise) Just like a tire is a huge compromise when it comes to long tire wear versus good traction. (Long tire tread life is at one end of the scale and good traction is at the other end of the scale. The closer that you can get the too extremes to meet, the higher the price of the tire goes.)
Now to address your 20” tire question and trailer towing. I realize that you are not talking a huge amount of weight, so just about anything would be “ok” but never the best idea when it comes to 20” tire options. Remember, if the 20” tires came from the factory, then the suspension has to be softer to accommodate the lack of cushion effect that you would get from a taller sidewall. (Softer suspension for towing a trailer? Not for me, thank you.) And if not from the factory then you will get a harsher ride and a higher maintenance cost every time it comes time to replace the tires. And since we are talking about replacement, YOU WILL be replacing them more often. The tread of the tire is the part touching the road and that is where the heat is generated. The sidewall of the tire dissipates the heat. So let’s see, wider (more) tread and shorter (less) sidewall. This sounds like a recipe for shorter tire life. Especially with the added weight of a trailer. Also, damage is more likely to happen to a shorter sidewall tire. If you do city driving, then the likely event of curbing scrapping the wheels and sidewall damage is highly increased. Not to mention pothole damage to tire and wheel. Again, you have less sidewall to cushion the impact of the pot hole edge and more likely to pinch the sidewall of the tire between the edge of the pothole and the rim causing a sidewall failure. Tire retailers/wholesalers love short aspect ratio tires because they get to sell more! In addition to the cost aspect, there is the traction aspect. You will also have less traction per square inch (same weight spread out over a wider area) which is detrimental when driving in snow and wet conditions, not to mention uneven grass at campsites. (The same thing happens with a dual rear wheel truck versus a single rear wheel truck having the same weight when trying to plow snow. The single rear truck will win every time, even though the dually has more traction edges on the tires.) I have even seen diesel pusher motor homes with dual rear wheels be stuck on wet grass at the race track. A person living in rural areas will experience less traction on gravel and mud, and the occasional rock will have the same effect of curbing or potholes.
My advice is to select the narrowest/narrower tire that will fit your stock wheels (same outside diameter within a few 10ths of an inch) AND carry the same or more weight. That will probably require going up in load capacity. (Standard to Load range “C” or “D”). Why a narrower tire when we are talking load capacity? When pulling a trailer or hauling a heavy or tall load you are looking to increase the sidewall rigidity. You are going to be inflating to max “tire” inflation which will “stiffen” up the sidewalls on the rear tires and give you less flex and rolling at the shoulders. This will decrease the sidewall flex which causes a tire to weaken, keep the heat buildup to a minimum and increase stability. You will then run 15psi less in the front tires for maximum stability. (Imagine a tire that is wider than the wheel and then imagine a tire that is the same width as the wheel. Inflate both tires to the same pressure. Which sidewall is going to give you the maximum stability? The tire that is wider will have some “rolling around movement” until the sidewalls will stop (come to the end) of how far the wheel can travel from one side to the other. The tire that is the same width virtually has nowhere to go when side forces (sway) occurs.)
My buddy had a Toyota 4-Runner with factory 17” wide low aspect tires from the factory. Not only was the tread design not adequate for getting him up the hill to his cabin, the width of the tire made normal snow traction a disaster. (even being a AWD/4WD vehicle) Plus he towed a trailer on occasion. I was able to find a load range “E” tire that was the same outside diameter and had a max width of the wheels that Toyota came with. Please note!!!!!!! HE DID HAVE TO REVISE HIS TIRE PRESSURES TO MEET RIDE AND LOAD CAPCACITY REQUIREMENTS. I was concerned that the ride would be too stiff. (A pickup truck with a long wheelbase is one thing, but a short wheelbase/light weight SUV would be something else.) However, when researching the tire weights, (original tires versus the increased load range) the load range “E” tires were only 2 pounds heavier than the originals because of the narrower aspect. (The higher the un-sprung weight, the worse the ride. Example being a loaded and unloaded truck. You add to the load (sprung weight) and the percentage changes to give you a better ride.) The 4-Runner did have a slightly firmer ride but in no way objectionable, and the difference in climbing the hill to the cabin was amazing. Needless to say, when those tires were worn out he replaced them with the same ones.
I know that you probably did not want to hear what I have said, and I have probably told you more than you wanted to hear, (AND TOOK TOO LONG TO TELL IT!) but these are my guidelines for tow vehicle tires. As an aside note: my sister has a 1500 Chevrolet truck with 18” low aspect tires. She has a camp trailer that she tows. Have we changed the tires form the originals? No. Has she been told (and is now religious) about the tire pressures? Yes. Will she be going to the same tires when the originals wear out? Absolutely not! (in fact we have already changed the tires on her camper even though they were just a little over 2 years old because one failed big time) But because she has only a Forest River R-Pod, the stresses are not nearly the same as a trailer that is taller or heavier.
One more note. If you are at a tire store that does not comprehend what you are trying to do and why find someone else or another tire store. Or you may run across someone who tells you all this stuff does not matter. They are being lazy and do not care about your concerns, nor are they having to drive your rig loaded. (The most enjoyable trips are when you are not concerned about what may happen or when you do not have to keep fighting an ill-handling rig.) Most of the “name brand” tire companies have the schools to teach these things, so a “lesser brand” dealer may not have the proper training. Sometimes a tire dealer that specializes in light truck tires will do this type of research as a matter of daily operations.
Good luck with your RVing!

Thank you for sharing this information. I really appreciate it.