12 valve gas mileage

I'm told that a 12 valve Cummins can get incredible mileage if the right bolt-on toys are installed. Is that true?

What kind of mileage is possible? What mods have to be done? Sure appreciate any insight.

Ben

Reply to
Ben Turner
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if you want the best mileage, you want a stock truck.

simply put....."more power means more fuel burned"

I've heard reports of 25mpg although I've never owned a 12v truck myself.

Reply to
Chris Thompson

"Chris Thompson" wrote

And then, there's such things as not voiding your warranty.

Steve

Reply to
Steve B

given the age of a 12v i doubt there's any warranty left on them.

Reply to
Chris Thompson

Isn't the 12 valve Cummins well beyond the warranty?

Plenty of claims out there from fuel additives (Stanadyne and others), tuners (Diablo Sport Predator and others), timers, tire pressure, etc... Of course one of the better ways to improve milage is driving it with the provobial egg on the fuel pedal or just keeping boost under 10#.

Go to

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and search and read to your heart's desire.

FMB (North Mexico with my '03 CTD HO)

Reply to
FMB

Some may disagree with me but some of those old 12 valve Cummins where the sturdiest and most reliable ones used in a P/U. They were low tech and not much to go wrong with them and were conservatively rated too which equalled a very long service life. Some of those old motors got some respecable MPG too in stock form.

----------------- TheSnoMan.com

Reply to
SnoMan

Gas mileage in a Diesel? sorry....

Also, its been well documented that some of the power add ons to the Cummins, regardless of engine evolution, improve mpg. While the "more power equals more fuel" axiom is true, efficiency plays a part. Diesels are able to change fuel curves, so different fueling affects mpg, many times in a positive way.

Reply to
Max Dodge

My stock 89 12 Valve, no intercooler, 354 rear, 5 spd Getrag gets over

22 MPG. And thats with almost 300K on it.
Reply to
Joseph Myers

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