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Old 01-01-2021, 04:56 PM   #58 (permalink)
racprops
Master EcoModder
 
Join Date: Oct 2009
Location: Phoenix AZ
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QUESTIONS:

A few questions...Which Express van is yours?? 2500 or 3500 or?

The transmission should be the 8L80E you said Allison...are they the same??

Second at 68 MPH what is your RPMs??

Thirdly do you know the rear end's gear ratio??

Thanks.

Rich


Quote:
Originally Posted by EcoVan View Post
I just posted this same response the large family hauler........
I have a 2017 Chevy Express full size with the 2.8 diesel we use for boiler service. With our standard vehicle weight around 7500 lbs ( about 2500 lbs of equipment on board) we get about 20 city and between 30 and 33.3 highway with A/C on at about 68 mph. 33 can be had with careful driving and some drafting behind semis. The 8 speed trans won't go into high gear until about 66mph, so you have to moving this speed. We've done no mods at all, and there is lots of room for improvement for aero efficiency ( bottom of vehicle is the usual mess, for instance). The engine produces just as much torque at 1500 rpm as the biggest gas v-8 at 3500 rpm so, it has plenty of grunt to get all that weight moving. This could give you plenty of room (up to 9 passengers) and a tank driving range ( standard 33 gal tank) of around 1000 miles. The "Diesel Place" Forum has some more info on this combo. These engine is also available in the Colorado/ Canyon SUV with similiar fuel economy. These other 2 don't have the Allison 8 speed trans the van does.

I worked out the math and the amount of money we save on fuel over the gas v-8 over the life of the vehicle will pay for the vehicle.
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