Question about fuel economy.

[Cellar Yeti]

Looking to possibly buy a van-based short bus with a diesel engine. Looking to go GMC/Chevrolet Savanah/Express, maybe an older G30 based bus. Was wondering if anyone knew the fuel economy of these rigs at 55-65mph.

I originally had an AWD Astro I lived in and a Tiger conversion of the Astro and was not happy with either but less so with the Tiger, my plan was to eventually add a high top to the AWD before it got creamed and totalled. Now with the AWD gasser I got 18 or 19mpg, if I were to add a high top, maybe 16 or 17mpg, with the Tiger XL I would be looking at 15 or 16 mpg.

Just wondering what I might be looking at for a short bus diesel.

Thanks guys.

[Tango]

A properly tuned and operated Cummins 4BT with the right gears can get 25-30mpg even pulling an 8-10K load. The gassers just aren't there yet.

[mony]

Hey Tango,
What gears would ya need to get that kind of mileage?

[Tango]

The tire diameter is the other big variable but...

with a 4.11 rear end
.73 Overdrive
37" dia. tires
1771 rpm will yield 65 mph

Check out the online gear/speed calculator here: http://www.csgnetwork.com/multirpmcalc.html

Hope this helps

[mony]

Excellent info Tango.

Thank you