I just bought this rig. Gonna pick it up in a few days. Got it at a steal, but it doesn't crank; however, I can fix anything. I have read about V10's getting close to 17 MPG. I know it's a simple (and complex) balance of easy air in, easy air out, programming, and the relaxation of the skinny pedal. The guy who claimed this (17 mpg's empty) swore by a fresh air intake, exhaust manifold back exhaust system and a programmer. Any tips? I use my trucks for hauling and I killed my 318 at 180,000 miles by working the poor thing to death (and mud bogging). Since I've had my current truck, I replaced my NV3500 three times before upgrading to an NV4500.

 

My Hemi 5.7 gets 10 on average

 

Never heard of one getting more than 15, and that was a single cab long wheelbase 2WD truck.


I'm amazed you finally killed that 318. lol

 

Are you trying to optimize highway mileage? I maybe get around 17 MPG highway on my 2500 with a freshly rebuilt 5.7. I highly doubt you could get that with an older V10 engine. Its probably geared for towing not MPG right now. But you should plan on a full tuneup. I don't know of many changes that people make that really help much in MPG. They are big trucks with lots of air drag. Not sure what kind of tires are on the truck but narrow smaller tires will probably be the best for MPG.

 

You don't specify what tranny/gearing it has. I've heard guys making out ok on the highway with the 6spd manual and 3.73 gearing but with the 4spd auto and 4.1, I'd be surprised if it broke 15mpg regardless of what's done to it.

 

Buying a V10 and hoping to get good mileage is like screwing for virginity.

 

I knew someone was gonna say this. I know that. I needed a better engine, I lugged my 318 to death. Now I use so much oil I don't need to change it, just a new filter and top it off. I bought this thing knowing I wouldn't see Honda (or even Cummins) fuel mileage. I just wanna curb it's appetite a bit.

It's an auto, but will be a manual by the time the repairs are completed. That will save a bit of fuel.

BTW, what's optimum cruising RPM's? 90% of my driving is highway at 65 mph. I want to re-gear to optimize it. I don't know the gearing yet.

 

You haven't stated what you're hauling, but whatever it is, the V10 more than makes up for the mileage loss in sheer power.

 

I haul it all: mini backhoes, skid-steers, concrete forms, dump trailers with 4 tons of concrete debris in them, in addition to the 37" tires I turn and have fallen in love with. I need the torque and must live with limited MPG's. My employer supplies all my fuel. But, my boss with his 06 Chevy Duramax gets roughly 14 mpg's. I want to get better than his so he can't complain about my new breed of engine.

 

The V10 has max torque at 2350RPM so you would not want your towing RPMs to run above that RPM. Most like 2000-2350RPM would give you reasonable towing performance. Max HP is around 4000RPM that is probably the RPM to climb mountains while towing.