RPM for best fuel mileage?

[seanpistol]

i've heard as high as 2100, but personally i think around 1800 is where i see my best mileage.

any input from you guys that have been driving these trucks for hundreds of years?

 

[TLBREWER]

i've heard as high as 2100, but personally i think around 1800 is where i see my best mileage.

any input from you guys that have been driving these trucks for hundreds of years?

My experience with 4.10 rearends and 5 speeds is anything over 2000 RPM reduces mileage exponentially. If your engine is in good tune and puts out enough power for highway cruising at your low altitude, then you should be getting the best mileage you can if you keep it at or below 1800 RPM...in my opinion. The guys with aux OD's and can cruise at say 1600 RPM probably get about 20MPG or better. When I bought my '92 F350 2WD CC, it had approx 150,000 miles on it and I could get 18 MPG with a 5 speed and 4.10's cruising at 2200 RPM. Course that was at 6000' altitude also.

Tom

 

[DeepRoots]

2100rpms would put me at 46mph.
yeah.... I bet i'd get really good milage there.

i get 15mpg at 2800rpms

 

[Agnem]

Definitely 1600 to 1800 for optimum economy. Makes sense, since this is also where the torque curve peaks. I've always maintained less than 2000 is best. I can't do that with the Moosestang, since it cruises at 55mph and about 2300 RPM, and it shows in the milage figures which are 17 to 18. It's smaller, and lighter, than the Moose Truck which gets 19 to as high as 23, turning on average 1400 at 55MPH with a manual transmission, overdrive and the same rear axle ratio.

 

[metrojd]

What am I doing wrong?

My 93 with a Ats 3.5 Powerstroke exhaust 5 speed and 4:10
In town I get around 10 mpg
on the highway I only get maybe 12 mpg.
I will admit at 65 its over 2000 rpm
But the way everyone talks I should be doing better.
209,000 miles I have only had it since 200,000 I dont know if its the org. pump and inj. or not .
would it help changing them?
Thanks
John

 

[troupp]

Well, I wish mine would even turn 2800, 55 is 1900 with 4.10's and 255-85-16's, But neither motor has ever been able to turn over 26-700. Dunno why.

 

[Black dawg]

a few weeks ago drove into a good wind for 200 miles with the camper on, cruise set at 70-75 boost was better than 10 the whole way, and egts were around a grand, with 4.11 gears got 11.5. this truck with out the camper or wind usually gets 16 or better.

 

[Agnem]

It would be interesting if there were GVW numbers to post along with these milage figures. Don't know if there would be a relationship or not.

 

[JeffMoss1]

2100rpms would put me at 46mph.
yeah.... I bet i'd get really good milage there.

i get 15mpg at 2800rpms

Do you seriously get 46 mpg!?!? How do you pull that off?

I've yet to take the van on a road trip, but when I do, the mileage is going to be key. Any tips?

~Jeff

 

[MTIDI]

I'm getting a solid 23 doing 70 mph at roughly 2300 rpm

 

[MTIDI]

Do you seriously get 46 mpg!?!? How do you pull that off?

I've yet to take the van on a road trip, but when I do, the mileage is going to be key. Any tips?

~Jeff

Read it again, thats 46 mpH

 

[JeffMoss1]

hahaha, that's awesome...it's sad that you had to tell me that...sry.

~Jeff

 

[Diesel JD]

Deep Roots,
Withg those RPM, that sounds like what I was getting when I had the 4.10s in my truck. I'm considerably lower than that now. If you can get 15mpg at highway speeds with 4.10s I would say you're doing quite well.

 

[typ4]

When we took the truck and camper on vacation we grossed out a 15,800lbs with the camper on and towing the wifes new wrangler, went from oregon up thru canada and out at michigan to wisconsin thru chicago suburbs and a good old nebraska style thunderstorm(thought we were blowin over on that one!!!] , then on to oregon, averaged 11.4 in 4900 miles witn brand new rebuild and2 quarts oil.
Camper only on 14.6 going to oregon coast in windstorm. Why the hell cant I go anywhere with the camper with no wind
The 460 got 6 so I am happy
Russ

 

[towcat]

Just for those who are wondering if you drove it like you stole it....
'92 F350 CC dually IC'd ATS with ZF5 and 4.10 posi, 7500lbs tare...
running 3k rpm maybe 3lbs of boost at 85mph steady. 13 mpg.
anything slower than that and I am going to sleep behind the wheel.
the pic was snapped somewhere on 80 E/B between Sacto and Reno.