How much tire pressure on my truck

[jayrzr]

I have a dodge 2500. pulling a 30 foot bumper pull. dry weight 7500. The michelin tires on my truck have a max psi of 80. What should I increase tire pressure to on front and rear tires on truck to?

thanks,

Jay

[Herk7769]

Correct tire pressure is based on load.

The MINIMUM tire pressure is located on the door post in most vehicles.
That pressure is a manufacturer's call based on curb weight and ride.

The correct tire pressure for your configuration is based on the actual load when you are connected, with WD bars (if used) installed so an actual tire load is determined.

My GMC 2500HD SIERRA (E rated Tires front and rear) uses 65 PSI in front and 80 PSI in the rear.

[jayrzr]

thanks

[donn]

I have to disagree with Lou here. Towing I always inflate to the max listed on the tires sidewall. I might make for a bit harsher ride, but the tires have a 100% chance of not being under inflated that way.

[Len & Cheri]

Originally Posted by donn

I have to disagree with Lou here. Towing I always inflate to the max listed on the tires sidewall. I might make for a bit harsher ride, but the tires have a 100% chance of not being under inflated that way.

X2 I max mine before the trip. That way I'm assured I will still be good after a 3-4 day trip. Longer and/or further trips require a re-check before heading home.

[Herk7769]

Max'ing trailer tires is a good idea if you seldom weigh your camper.
Camper weight varies every time you go out and unless you weigh every trip it is hard to determine what the proper inflation pressure should be.

By using max rated pressure, you will always get 100% of the load bearing capacity of the tire. You can still lose a tire for many reasons not related to pressure (road trash, internal failure, or curb strike).

You will also get stiff side walls and a "bouncy" camper ride. This can cause avoidable breakage inside. Additionally, with over inflation for load you might not get complete tread to pavement contact resulting in asymmetric tread wear (center worn more than edges).

Having said that, most OEMs put that absolute minimum quality and rated tire on their campers. They will ONLY carry the max rated load of the camper when fully inflated. So if you routinely max out your camper (as I do) maxing out the pressure is the "right" thing to do.

However, if you replace your OEM tires with a higher rated tire (replace C rated tires with D for example), your tires can carry more load than you need. In that case, using the optimum inflation pressure for load will result in the best ride, longevity, and tread wear.

Remember that you still can not exceed the max rated weight of the camper, just have a better (softer) ride, higher ply rating (for road hazard protection), and can utilize a weight based inflation schedule.

As to the tow vehicle, the OEM minimum and load based inflation schedule is still optimum IMHO.

[acadianbob]

Originally Posted by donn

I have to disagree with Lou here. Towing I always inflate to the max listed on the tires sidewall. I might make for a bit harsher ride, but the tires have a 100% chance of not being under inflated that way.

X3. Most maunufacturers are more worried about the ride than they are tire wear or load capacity. I run max in my car and truck at all times. Got 70M miles out of the original tires on my F150. Nice even wear.

[Herk7769]

Originally Posted by acadianbob

Got 70M miles out of the original tires on my F150. Nice even wear.

70 Million miles is quite an achievement.
Even a paltry 70K miles is awesome!

[Hybrid21SS]

I installed E rated tires on my 1500 Chevy Avalanche and run both front and rears at 65 lbs and been very happy compared to the crappy stock C range tires...

[flyrotor]

I have the Dodge 2500 as well with Michelin E rated tires, in the 2011 model the TPM system indicates actual pressure on all four tires individually and is displayed on the dash. It also has a Light load setting and a Heavy load setting. Light load is based on a driver and one passenger, and 200 lbs of cargo. (as per the Users Manual)

When I monitor the Heavy load setting, I will get a low tire pressure alarm if the rear tires are less than 80 psi (cold) and 70 on the front tires.

I figure if I have ~700# tongue weight and ~300# additional camp cargo, plus a full tank of fuel (250#), 5 occupants, and 3 kayaks (200#) on the racks, I use the Max load setting.

When towing, I put 71 PSI in the front tires and 80 PSI in the rear tires.

So, It's pretty easy to see Lou's point of view with my scenario

[acadianbob]

Originally Posted by herk7769

70 Million miles is quite an achievement.
Even a paltry 70K miles is awesome!

HA! I'm a purposeful holdout Herk! Remember when M was 1,000 and MM was 1,000,000? The computers came along and people started using K for 1,000. K is actually 1,024. M comes from Roman Numerals. M is 1,000 forever for me. HA!