Greasebeast

[lovemysan]

Ahh! You picked my favorite truck. I should know

http://www.dieseltruckresource.com/p...ser=31059&sl=l

She met sad a fate. But now she's a daily driver for another cummins fanatic. I never had an odometer so I don't know the mileage it got. I removed 3 leafs from the rear spring packs and install monroe gasmatic shocks to improve the ride. I also raised the bench seat 2 1/4" and added 10 degrees of recline. Overall it was a vast improvement in ride.

[omgwtfbyobbq]

Originally Posted by theclencher

This comment applies to both gas and diesel engines.

To an extent. The bar/rpm BSFC maps are very favorable for diesels, by quite a bit.

[The Toecutter]

Indeed. But the difference is much smaller than most people think. Going after aero drag and weight will yield much larger gains in economy, no sacrifice needed.

[omgwtfbyobbq]

Originally Posted by theclencher

That doesn't change the fact that a small diesel appropriately sized for the load will be more efficient than a large one.

The bottom line, if you are using 8 cylinder equipment to move a single occupant, it ain't gonna do it as efficiently as something more appropriately sized.

Well... yeah, but that's more a matter of use than anything else. If someone sold garbage trucks to the public, I wouldn't be surprised if some nut commuted to work in one. When someone starts commuting in an RV, I'd think it's about time for the mass sterilizations.



The point I'm making is that the majority of load reduction for a diesel is fairly nice until pressure gets down to around a fifth of the intake pressure range, then it runs into the 300-600 range. A gasser will do the same, starting from half of the intake pressure range, except for atkinson/miller cycle. So.... small changes in drag/RR can have significant changes in FE provided they don't drop the engine into that low end BSFC portion. Otoh, gassers have a few steps forward, one step back problem because of the really quick increase in BSFC compared to intake pressure.

[The Toecutter]

VW screwed up their 1L when they failed to put a V8 in it!

I know you're being sarcastic, but I actually would agree with that statement. Given that the 1L is an extreme, a V8 would drop FE by 50% or more due to such a low load operating point for normal use, but even still, the performance and still high economy combined would be impressive. It wouldn't be a 250 mpg miser, but a 100+ mpg miser with a V8 would still be nice.

But if you have less extreme cars, say, a V6 Mustang(22 mpg combined, 210 horsepower) versus the V8 Mustang(20 mpg combined, 300 horsepower), or the L4 Camry versus(27 mpg, 158 horsepower) the V6 Camry(25 mpg, 268 horsepower), the differences in FE between the les powerful and more powerful versions are around 10%, while the more powerful versions tend to have horsepower increases over 50%. If you look at the same models of car, truck, or SUV and compare engine options, the difference in FE between the most powerful and least powerful models isn't that great, while the difference in peak horsepower available is huge.

[The Toecutter]

I made that statement under the assumption that the needed modifications would be made. Perhaps 300-400 pounds would be added in weight, drag wouldn't have to change. To fit this mammoth engine, the car could be elongated for a better taper. With proper design, this need not increase aero drag, but attention must be made so that the extra skin friction from the longer taper doesn't kill the Cd.

A V8 1L sounds like the good kind of disaster, that doesn't get full traction, pulls 9 second 1/4 miles @ 140 mph, and twists sideways when you floor it!

I'd rename it the Dominatrix. It will punish you harshly if you're bad, and will reward you with punishment if you're good, the latter much to your delight.