sustained top speed

[Kwai]

In Texas 250 miles is a short trip for a 2.5 ton. I have driven my trucks 500+ miles at 50-55. Your butt will break before the truck does.

 

[Boatcarpenter]

I'm with several of the others that have posted in this thread. Everything seems to be right in a comfort zone with the engine, truck and me at about 51 to 53 MPH. She's a one hand on the steering wheel driver, vibes are minimal, exhaust tone is nice and I really get to notice things by the side of the road that I miss at 70MPH. They are what they are, relax and enjoy the ride.
BC

 

[avengeusa]

mine likes 50 ish, i have been to 55, but i want mine to last, so 52-52 is cool with me

 

[jwaller]

I run my deuce at red line for hours on end and have done it for years. good maint will let you do that.

 

[Ferroequinologist]

I usually run mine around 50-55, but I was towing a M35 for Gearspec this weekend and down hill I got to 62mph and 2700rpm, but not for extended periods. But I will cruise with the M109 right at 2550 all day, no real issues. Mine is turned up by the gov, so if I punch it it will hit 2700-2800rpm easy. I very very rarely do that though.

 

[GoFastCrackPipe]

I just finished a 1800 mile recovery (Ft. Dodge, IA to Portland, OR) and ran my new M35 at ~52mph/2400rpm for about 12 hours a day for 4 days with no issues. I also averaged 9.8mpg. The only problem I had was that my a$$ was sore and numb by the second day and just got worse from there... still worth it.

 

[randyscycle]

I find that I can run at 55MPH on flat ground in my M35A2, but if I keep my foot in it for an extended period, the pyro temps will creep up around 1100F doing it. The engine sounds fine the coolant temp is great, the oil pressure is fine, and the truck drives OK, but the exhaust temperature tells the real story.

If you really plan on keeping the truck up close to the redline a lot install a pyrometer.

 

[Green_gator]

I just did a 1,200 mile recovery of an M35 and did a 1,100 mile recovery of an M109 last spring. I can tell you that the M35 without the tarp on it runs a lot easier then the flying brick that it an M109. I know that trucks will run a bit different even if both are the same model and stock. I have to agree with Boatcarpenter. Take your time and enjoy the ride.

 

[peecook]

if you can get it to 55mph on flat, let me know. mine gets up to 53mph/2400rpms and that's the best it does. most of the time I'm at 50mph/2200rpms. i have driven mine 350 miles (only stopped for gas but her kept running) and no problems. also made a trip where i towed a m35 and ammo trailer behind that, 160 miles no problems, except that i was only doing 20 in the Hampton VA tunnel.

 

[scooter01922]

Mine does 55 without any real issue, not too hilly around here and i need to actually watch myself or the speed starts to creep closer to 60. At least for the first few miles after that i get back into the driving a deuce rythm and keep it somewhere 50-55, usually closer to 55. Has yet to get below 50 or so on the hills in the highway here. I think you may want to check out your filters peecook.

 

[mastergunner53]

Hi all,
lotz of good stories!! You guys with the sore butts, do you have an air ride or spring ride seat?
gofastcrackpipe, wow that is a loooong drive! Glad to hear no mishaps! I'll be converting it to a motorhome. Installing shower, toilet ,kitchen facilities, etc....

 

[jesusgatos]

I just drove my M109 back to Bend from northern CA (about 250 miles) and except for the hills, maintained 50+mph the whole way. It topped out at close to 60mph, and seemed happy enough to cruise at 55mph. The engine sounded best at about 2200-2300rpm though, so I settled-in at about 52-53mph for most of the drive.

 

[Recovry4x4]

I have no problem running mine at 58-59. If i'm in no hurry 52 is a sweet spot but if I gotta scoot, I'm gone! The road noise goes up considerably once you surpass 45.

 

[Brock Steel]

I agree 50 to 52 MPH is the zone...p.s I still can't feel me bum.........

 

[IHASFIP]

I haven't made any long trips. I plan on making a 250 mile trip during Memorial Day, but so far on 40 mile trips I run 50-55. In the hills I let it drop down to 45 or so because the pump is turned up and I have no pyro yet. I do know cruising at 55 there is not really any smoke, just a very light haze. Even if you step on it you get very little smoke. That is at WOT. But in town, it will smoke alot while running through the gears.

D

 

[Jake0147]

One thing I did notice was that it ran much better after about 2 hours of constant use, seemed to have more power. Maybe I just burned all the old junk out of it?

Mine seems that way too... It's not a sudden change however. It almost "sounds" happier too, when you're cruising with the engine at or near redline... Not like you turned it up or anything, but more like the engine finally warms up to operating temperature or something...

 

[ohnuts]

2350 rpm at 61mph for most of ten hours for a 8.9 gpm trip, can you say sweet. My M185A3 from Camp Dodge to Indianapolis IN. Its faster than my M35a2.

 

[olly hondro]

A little off topic: so you're poking along the interstate at 52 MPH, do you run the 4 way flashers, a yellow becon, what do we do to avoid getting rearended by an 80,000 lb semi doing 80 mph?
Alex

 

[grounded]

i just run down the interstate in the right hand lane. period. usually around 52-57mph depends on where she is at. but i also have run WOT and not had any issues over a long period of time

 

[OPCOM]

I believe the truck will run for the life of the engine (what's the record?) at 55MPH. Done about 9000 miles solid on highway road trips, at or near 55. I run 55 whenever possible but not often over.
3000 of it was with 9.00x20's, so I was close to the redline.
Since then, I use 11.00x20's and the truck does 55 but the engine spins as though it were doing 50. Going to 11.00's is a worthwhile and non-farb MWO that will help the engine at highway speeds.
I would like to do 60-65 for the long trips. To do this larger tires are required. There are 1 or 2 people who say they run 65 on stock tires all the time, but that's over redline.

The point is that I cannot blame one single failure on doing 55MPH for thousands of miles. IMNSH opinion, 5th gear in the transmission is a weak point and is as likely to break as the engine at redline.