Forum Discussion

RFYeager's avatar
RFYeager
Explorer
Feb 21, 2014

Class A Fuel Mileage

I am trying to find out the average fuel mileage for the new Tiffin Allegro Red 34 Diesel. It has the 340hp Cummins with the Allison 2500 transmission. However, it only has 660lb.ft. of torque (probably due to the gearing of the Allison 2500). I tow a Grand Cherokee, which is approximately 4200 lbs. Just trying to make general comparisons when I go to look at buying a new (or different) RV.

I thought that wouldn't it be great if there was a forum or some type of chart where members can post their fuel mileage experience? I understand that everyone's driving styles are different, at different elevations, at different temperatures, etc. I'm just talking about a general average.

For example, I have a 2007 Fleetwood 38V with a CAT 300hp diesel and a Allison 3000 transmission. I get on average (towing my GC) 7.2 mpg. without the Toad, 7.7mpg. These numbers are driving with my cruise control set at 62mph.
  • I suspect you'll be getting about the same as your Fleetwood had, or in the 7 mpg range.

    I get between 10 and 11 mpg, but I have a mechanical 8.3 and a 26K lb coach. The newer electronic engines are not as efficient and the smaller engine (the ISB) I believe gets slightly less MPG than the ISC or ISL. Most have posted they get between 7 and 8 mpg, and that's what my friends with similar power trains get.

    More important factors include how you drive, the road conditions, and the weight of your coach & toad.
  • When my tank gets to half full, I start looking for a fuel station and fill it up. I have no idea what the fuel mileage is.