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Old 06-15-2015, 02:17 AM   #25 (permalink)
bondvagabond
EcoModding Apprentice
 
Join Date: Nov 2009
Location: Austin tx
Posts: 115

vandle - '93 Ford E-350 Xlt
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Quote:
Originally Posted by oil pan 4 View Post
Does this 7.3 not have a turbocharger?
If you are not going to install a turbo you are throwing away a 10% to 20% fuel economy increase.
Decreasing the final drive ratio on a non turbo diesel is going to increase exhaust gas temperature as you try to work the engine harder at lower RPM. You will just end up blowing more heat out the exhaust.
Have you found any specific data on this? I have always heard that turbo diesels were more efficient, but the only apples to apples comparison I can find that is not anecdotal is the 1.6 na and turbo vw diesels. All other examples I know of the turbo model has lower compression ratio, so more than one variable is being changed. In the vw diesels I mentioned the non turbo gets 9% better fuel economy on the EPA rating. Keep in mind the vw diesels and my pre powerstroke 7.3 are relatively high compression mechanical diesels. One of the guys with a 2007 cummins on here is pushing close to 60mpg which is insane. But is that the turbo? The computer controlled fuel system? To many variables for me to guess being only a shade tree engineer. Big orange truck is getting 38 mpg tanks with my motor and no turbo now that he got a zf5. And he actually hauls a lot more weight than me.

If you can prove to me a turbo will get me more mpgs in my application I would be stoked. Also, if you had a specific model of turbo to recommend that would be optimized for efficiency not power I would be very great full. My motor had plenty of power for me with the slipping auto trans, I'm sure with the manual I will be even more satisfied with current power.
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2007 Silverado 3500 classic duramax diesel, Allison 6 speed auto, extracab long bed. Doing head gaskets, will probably do econo tune and aero mods next.

Mad max would have driven a metro
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