Interstate cruising speed

[BehindBars]

Originally Posted by jgahlhoff

About 62-65

Same here. 62-65 MPH is a safe and economical speed for me on interstate highways.

[007matman]

As fast as I want to.

I can get 12-14 MPG all day with my F350 Turbo-diesel.

Typically, it's about 70 but if traffic is pushing I'll go a bit faster. Save me the lecture on china-bombs.. they do just fine. Just gotta check the tire pressure and swap them out every 3 yrs.

[aceinspp]

Originally Posted by Oldbears

Right hand lane @ 62-65 mph. Saves gas (usually gain 1-2 mpg around the 62 mark), and its safer.

X 2 definitely get better mileage. Later RJD

[Jim34RL]

Originally Posted by 007matman

As fast as I want to.

I can get 12-14 MPG all day with my F350 Turbo-diesel.

Typically, it's about 70 but if traffic is pushing I'll go a bit faster. Save me the lecture on china-bombs.. they do just fine. Just gotta check the tire pressure and swap them out every 3 yrs.

Is that hand calculated fuel mileage or from the LIE-O-METER in the truck?

Also, what do you pull?

I can tell you for a fact the faster you travel with the higher Boost pressure level is required to propel you down the road, the more fuel you will burn to achieve that speed.

I have just as big an engine 6.7L with more HP/TQ than your Ford does, but I do not need to travel that fast just to say I can! I keep my Boost pressure around 10 PSI as I pull my trailer, this provides my best fuel mileage.

We will both get there it might just take me a little longer but I will get there, traveling at 65MPH.

[Justice12t]

Strange...running at my speeds my boost is about 2-4 psi cruising ...but hey more power to you if you'd rather watch your boost pressure than the road...

[NMWildcat]

Don't think I've ever even noticed my boost. We avg 10.5mpg over the entirety of most trips. That includes different speeds, wind directions, uphill and downhill. Always seems to come out to an avg of 10.5mpg.

[Reverse_snowbird]

Depends....

If we're towing a trailer, 60 mph gives us better gas mileage and the ability to recover from passing 18 wheelers easy.

If we're in our class c motorhome 65mph. Gas mileage seems to decrease dramatically after that.

I have no data to support my view. It's just I feel comfortable driving at those speeds.

[007matman]

Originally Posted by Jim34RL

Is that hand calculated fuel mileage or from the LIE-O-METER in the truck?



Also, what do you pull?



I can tell you for a fact the faster you travel with the higher Boost pressure level is required to propel you down the road, the more fuel you will burn to achieve that speed.



I have just as big an engine 6.7L with more HP/TQ than your Ford does, but I do not need to travel that fast just to say I can! I keep my Boost pressure around 10 PSI as I pull my trailer, this provides my best fuel mileage.



We will both get there it might just take me a little longer but I will get there, traveling at 65MPH.

6.0 fully studded, tuned, and Bulletproofed.

Hand-calculated.

33' Rockwood, 7500lbs.

Higher HP and torque than mine? Maybe.. see the first comment. Doubtful.

[NMWildcat]

Originally Posted by 007matman

6.0 fully studded, tuned, and Bulletproofed.

Hand-calculated.

33' Rockwood, 7500lbs.

7500lbs behind a 1 ton? I'm surprised you don't get better mpg than that at any speed or boost!

[Volvodriver]

Sweet spot on the Volvo is 63 mph in 12th gear. It hums along and the display shows an average of 8.5 to 8.8 when towing. Display goes up and down according to road and weather conditions. I will go faster to pass but will slow down for tailgators. Decal on back of rig says " sorry for driving so slow in front of you ".

I am also a graduate of the school of "rig and tractor tire blow outs" and I know bad things that can happen at any time out here on the highways and byways.

Dave

[007matman]

Originally Posted by NMWildcat

7500lbs behind a 1 ton? I'm surprised you don't get better mpg than that at any speed or boost!

I've seen others that claim better. However, my particular truck always right around 14.. sometimes 15-16 if not towing. I've heard claims of 20 but personally, I've never seen that.

Beats the daylights out of my Esky.. 6-7 mpg stopping every 2 hours for gas.

[ppine]

I just returned from Elko and I-80. The new speed limit is 75 to 80. When not towing, my Ford 7.3 is happy at 75 mph or so at around 2200 rpms.

When towing my outfit weighs around 12,000 pounds truck and trailer together. The trailer tires are rated for 65 mph, so that is max speed.

[bikendan]

62-65mph

[Cowracer]

Originally Posted by Jim34RL

I can tell you for a fact the faster you travel with the higher Boost pressure level is required to propel you down the road, the more fuel you will burn to achieve that speed.

Not so fast.... I can absolutely show you where my old Excursion gets more boost and better mileage running at 72 as opposed to 66. At lower speed (and lower RPM) I'm off the bottom end of the boost curve with the current turbo I have on it, my EGT's are way higher and fuel burn is noticeably higher. At 72, I'm getting to the sweet spot that 7.3s are most efficient, about 1900 RPM, boost is up, and EGT's are down. I am fanatical about checking mileage and it's roughly 7mpg at 66 and just a touch over 8 at 72-73. 75 seemed to be the point where it started coming back down again and drops like a rock above that.

Each truck is different, but sometimes slower is less efficient. Haven't pulled enough with the new Ram to know where the most efficient spot is, but it seems awful happy and relaxed at about 68.

Tim

P.S. and I assure you, you don't have more HP or torque than I do...

[merrykalia]

Both DH and I tow between 65 and 70, if the limit is that high. If it's at 55, we travel 57ish. We might go a bit faster if we are passing, especially going up a significant incline.

[24_Byron_fan]

It depends who's with me. 65mph tops with the family just because they'll whine at me if I drive slower. If I'm alone I'll go as slow as 55mph. Life is easier when you're not in a rush. My TT's tires are rated for 75mph and my truck has no problem holding that speed with everything fully loaded for a trip but the mileage is only 8mpg. I'd rather back it off to 55mph and get 11mpg. I'd rather get that 100 extra miles out of the tank than arrive a few minutes early.

I have a 2018 F150 3.5EB with the 36 gal tank towing a Salem Cruise Lite 282QBXL.

[TitanMike]

I find the posted speed for vehicles towing to be just right for me.
Last trip took me through States with towing speed as low as 50 and up to regular posted.

While I CAN tow at 70 mph I find 60 to be both comfortable and economic. I find a lot of similar minded RV'rs keeping me company in the RH lane.

[Dakota 1120]

Used to not exceed 65 MPH w/factory camper tires but put on Goodyear Endurance with speed rating of 86 MPH.
Therefore, now I usually run about 70 - 75 MPH and the Interstate speed limit in South Dakota is 80 MPH. :-)

[Jim34RL]

Originally Posted by 007matman

6.0 fully studded, tuned, and Bulletproofed.

Hand-calculated.

33' Rockwood, 7500lbs.

Higher HP and torque than mine? Maybe.. see the first comment. Doubtful.

Yes, I am not stock either I am using a Smarty S67 programmer on my truck. CaTCHER level 3 adds 60HP/120TQ measured at the rear wheels over stock which I tow at. I can go all the way up to 170HP/350TQ as measured at the rear wheels over stock if I wanted to.

That is why I watch all of my gauges as I am towing my trailer. This includes EGT's, Boost, Transmission temps, oil pressure, coolant temps and engine rpm's.

If it is a Ford 6.0L and a 6.4L engine it is never built proof, it is a Ford by the way. You know what they say don't you, 90% of the Fords built are still on the road today, the other 10% did make it home.

[B and B]

I run 85 KPH on 80 KPH roads that all 2 lane. Keeps people off our butt and trying to pass on curves.
4 Lane 400 series hi-ways I do 100 KPH. Right lane, let them pass.