turbo fuel economy

[Bazman]

My rear mount turbo results are just in after 20 hours dyno testing plus road testing to get driveability sorted re cold starts, response, lean burn cruise etc. Economy at cruise is identical pre turbo and post turbo. i.e. adding the turbo has not cost any fuel at cruise conditions.

Factors that led to this include - proper sizing, bigger headers and exhaust system, free flowing low back pressure intake piping, and likely more fine tuning than the pre turbo motor had - but still ending up running much the same AFR and timing as before.

So it can be done Mind you I was actually trying to get an improvement... so actually I failed at that I'm blaming the cam

[Johnunit]

Warpspeed's sentiment is worth repeating:

In almost any car, but especially an older design and likely aging pickup, the biggest/lowest hanging gains to be had are in the chassis, aero, gearing, tires, etc. The engine, especially if it's the engine that was factory spec'd as the economical choice, is a long way down the list. You could probably spend a lot of money on that engine before matching the gains of some LRR (low rolling resistance) tires at 40-45PSI, a 2-3 inch airdam below the front bumper, and some smooth(er) wheel covers. That's just generic stuff off the top of my head. Certainly if you're just talking weight of vehicle and displacement of engine low 20's mpg on the highway should be VERY beatable in a 2.3 ranger.

[mbrooks]

on my '99 ford powerstroke i usually get around 18mph without any boost on the highway. when i put a programmer on it and ran 3-4lbs. boost just running down the highway my mpg went to shit. on my tdi i run it at 1900rpm and i can feel the turbo occasionally go into boost, must be right at the threshold, but this is where my mph is fairly good, above that and it goes down. stay out of the boost and your mph shouldn't be affected from my experience.

[englertracing]

Warpspeed's sentiment is worth repeating:

In almost any car, but especially an older design and likely aging pickup, the biggest/lowest hanging gains to be had are in the chassis, aero, gearing, tires, etc. The engine, especially if it's the engine that was factory spec'd as the economical choice, is a long way down the list. You could probably spend a lot of money on that engine before matching the gains of some LRR (low rolling resistance) tires at 40-45PSI, a 2-3 inch airdam below the front bumper, and some smooth(er) wheel covers. That's just generic stuff off the top of my head. Certainly if you're just talking weight of vehicle and displacement of engine low 20's mpg on the highway should be VERY beatable in a 2.3 ranger.

At one point I wanted to skin the bottom of the truck with aluminum, free aluminum my friend had dozens of road signs .125 aluminum. Makes great panneling.
Is that worthwhile?

[Warpspeed]

Is that worthwhile?

It depends on how good or bad the aerodynamics of the rest of the vehicle are, and how fast you normally travel.
One very worthwhile thing to do with a pickup truck, is to fit a cover over the bed.

[Johnunit]

The front part of the underside of the truck is typically most important. Basically the front suspension and the engine assembly.



I hope I'm not breaking any rules here, but you may try www.ecomodder.com for ideas on non-engine related modifications. There are several people on there "aeromodding" pickups of various age and size to good effect.

[Dave Flanders]

I can add some real world experience here. Don't be too quick to discount the old Ford EEC systems. I've got a 1941 Ford Tudor sedan with a basically stock 2.3 Turbocoupe driveline. We took it on a trip to NJ once and got a consistent 31 mpg. This was through the mountains of PA with the boost usually running from 5-10 psi and turning 3000 rpm at 70mph due to the 4.30 gears. At 3500 lbs it will run easy mid to high 13's at the track so it's still kind of fun for a street car. Yeah the newer stuff might be better but there is a law of diminishing returns and if you're concerned about fuel mileage spending a lot to achieve it might be counterproductive.

[TTXPC]

I have not long finished turbocharging a 5000lbs cabover traytruck with a 302w and non intercooled s400 on straight propane, economy has slightly improved from 7.5 to 9mpg !
This is driving as normal with plenty of positive manifold pressure situations, and just giving it a hard time just for the fun of it