5,000 pound diesel, 26mpg at 65mph

[slowmover]

I find that 55 really does feel slow . . but 58 not as much. Try it out and tell us about it (conditions, rpms, etc). Have you actually scaled that truck with driver, full fuel and the usual junk on board? And, hey, a pic or two!

I could probably fill up out of town after the truck has achieved full 30-mile warmup and drive a long low-traffic/low-wind route and nearly break 30 mpg. Mine also outweighs yours by more than a ton. I know I'd like to see what a 1st Gen can really do!

How's the average, overall?

.

[JQmile]

I guess I'll expand a little more since there seems to be interest! The truck is not stock, and not even close. It has a 62mm S300 turbo, 4-inch downpipe, ARP head studs, an external wastegate, and built 47RH trans with a manual valvebody, transbrake, and billet input shaft. On two stages of nitrous, the engine has made 514rwhp, but that was with some issues, namely 7 degrees of timing (my fault) and a 20% slip rate from a non-lockup converter. With the lock-up trans and 20 degrees more timing, I'm hoping 700 to the wheels will be possible.

The truck wasn't designed for fuel economy (hence the 300% larger than stock injectors and black smoke at full throttle) I just figured it would be neat for people to see what's possible with diesels. The truck weighed 4850 with a 1/4 tank and 727 trans, so I figure it's a bit heavier now. I go by EGT which seems to be a pretty good indicator of fuel economy. Since I had a 100 degree drop from 65mph to 55mph, I think it will do even better at 55mph, but I'll try to do a test sometime soon to verify that.

My average fuel economy sucks, because I have a 2 mile drive to work (including warm-up) so walking to work usually gives me the best fuel economy

Here's a couple pics of the truck, its main goal is to be a cool sleeper. Thanks for the responses.

[instarx]

Originally Posted by UFO

That's very good, higher than I would expect. But I have a Mercedes 240D and a Jeep Liberty both nearly 5000 lbs, and both are capable of nearly 30mpg at 60-65 mph as-is, no aeromods or driving techniques.

What, did you get the special edition 240D with the spent uranium frame? Most 240D's weigh in at 3,000 to 3,300 lbs.

[Dave's Civic Duty]

JQ,

No intercooler? Is that your design on the intake manifold. I just love Dodges
w Cummins diesels. Your 1st gen looks sweet, nice sleeper, even stock hubcaps, cool!

How difficult was the trans update/swap?

CTD!

Nice work,
Dave

[Backtobasics]

Project Rust Bucket!

I didn't pay attention to the screen name.

Do you still have the Chevette?

[JQmile]

I sold the Chevette to some glass blower hippie dude who headed up to Oregon with it. Kinda wish someone would have bought it and eco-modded it (it was for sale on here) but nobody wanted to pay 2K for it.

The trans swap isn't all that difficult as long as you are patient, and basically have access to a wrecked Second-Generation donor truck because you'll need a lot of other parts besides the transmission itself. The 89's were non-intercooled, but the intake pictured was actually built by a buddy of mine for his truck, and I snagged it when he went to compound turbos.

If you were to build a 1st-gen Dodge for fuel economy, I'd look for a 91-93 model with an intercooler and overdrive trans, and then try to find a 3.07 rear out of a 89-90 model. Just easier that way.

[UFO]

Originally Posted by instarx

What, did you get the special edition 240D with the spent uranium frame? Most 240D's weigh in at 3,000 to 3,300 lbs.

It has a 5 cylinder turbo diesel 617.952 engine and the entire driveline from a 300D. I'd be shocked if it weighed less than 4000lbs, it certainly feels like a tank. But I could be wrong, and it just has terrible aerodynamics or a lossy transmission.

[Dave's Civic Duty]

Originally Posted by Backtobasics

Project Rust Bucket!

I didn't pay attention to the screen name.

Do you still have the Chevette?

Is this that same one that is in Diesel Power magazine? One of the writers has a diesel Chevette & Project Rust Bucket too. You're from KC & the mag is based in LA, so I'm thinking it can't be you. Long commute!

Dave

[Dave's Civic Duty]

Originally Posted by JQmile

I sold the Chevette to some glass blower hippie dude who headed up to Oregon with it. Kinda wish someone would have bought it and eco-modded it (it was for sale on here) but nobody wanted to pay 2K for it.

The trans swap isn't all that difficult as long as you are patient, and basically have access to a wrecked Second-Generation donor truck because you'll need a lot of other parts besides the transmission itself. The 89's were non-intercooled, but the intake pictured was actually built by a buddy of mine for his truck, and I snagged it when he went to compound turbos.

If you were to build a 1st-gen Dodge for fuel economy, I'd look for a 91-93 model with an intercooler and overdrive trans, and then try to find a 3.07 rear out of a 89-90 model. Just easier that way.

JQ,

It must be you, from Diesel Power. Great mag, I read it cover to cover every month. I read all the articles on each of your vehicles. You were thinking about putting a diesel in the Nova as well.

I was looking at the wrong post for my response to KC Kansas, sorry!

Dave

[JQmile]

Yup, I'm the Associate Editor of Diesel Power mag. I'm actually pretty close to finished with Project Rust Bucket as long as it does what I want to on the dyno and at the dragstrip...then it's time for (finally) paint!

Before I retire it, I'll do a fuel economy run at 55mph though, just to see if I can break 30mpg.