Class C performance in the mountains

[sundancev]

Hello all RV'rs.  After 10 years full timing in a 39' Fleetwood Providence with a 350HP Diesel pusher, we downgraded recently to a 2007Winnebago Spirit with a Ford V-10.  It is built on a 2006 E450 chassis.  We consistently averaged 8 miles per gallon towing a 5,000 pound Ford Explorer in almost any venue E-W and W-E for some 180,000 miles.  Yes we enjoyed the ride.  Unfortunately age has its burdens.  Mine being loss of 50% of left eye sight and prognosis not very good.  So, we bought a house again and decided to rv perhaps 3 months a year.  Bought the smaller coach that my wife was a little more comfortable driving.  Over time we found as bridges on the Interstates were being rebuilt througout the West, many of the Interstates had sections where traffic was a narrow two lanes.  When a big semi was coming from the other direction, perhaps inches away from mirrors touching my wife would become understandably nervous.  So in anticipation of the day when she would do all the driving, we downsized.  When we bought the Spirit in very good condition, barely used with 19k miles on it, we thought mileage would be perhaps better than with the big heavy Providence.  First real trip, mileage was 6.7 mpg at average speed of 65 mph.  So we dropped down to 55 for next leg and came in with 7.8 mpg.  Does this seem normal to anyone.  I think it is low.  Motor seems to purr.  We have 6 brand new Michelins so tires are not a problem.  Some days wish we still had high mileage Diesel which actually is just broken in.  This Ford V10, I thought at 19k would also just be broken in.  Thanks for any advice.  Paul

[jleamont]

Paul, sounds about right. I had a pickup with that engine and it was consistently at 9.6 - 10.0 mpg empty. Much less vehicle than what you have, same power train. 
we had a Coachman Santara Class C before the DP we have now and we never got more than 7.0 I even installed a Banks Power Pack, ran better didn’t do anything to the MPG’s. 

Edited July 5, 2021 by jleamont

[wildebill308]

That mileage sounds about right. Do you have the 6 speed transmission?

Bill

[manholt]

I have found over the past 54 years and 18 Class A's, there is not more than 1.5 to 2 mpg difference between gas rig or DP.  Size, weight, HP and terrain is the average determining factor!  You found that speed (wind resistance) on a class C, makes a big difference in mpg!  Sit back and enjoy the ride, at a slower speed, you'll also get better road manners.