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Squeezing the best mpg from a RV

As a senior citizen on fixed income and an ardent RVer, I am on a quest to gain the best milage from my RV. I have a 1997 Coachmen 23' Catalina (class C) powered by a Ford V10 engine. I have taken care to have the engine, tires and vehicle well maintained and in tiptop condition and consistenly get about 10 -11 mpg. After talking with outhers about this engine and chasis, Ford E 350 @ 10500lbs gw, I am getting good mileage but I really want to try to improve it further. My current strategy is to reduce my road speed down to an optimum point to squeeze the very best mileage possible from the rig. I currently keep my speed at approx. 60 mph but am willing to reduce it further if I would get better mileage. So, what speed would you suggest? Since I am retired, I am normally not in any hurry to get anywhere if it will allow me to continue to use the RV.


  • I would not reduce speed much more, you'll risk being rearended by an inattentive driver. And it wouldn't make that much of a difference, anyway. 10,500+ lbs is hard to improve much, you're doing what's recommended. Make sure the tire pressures are measured when cold (sure you are). There are expensive engine modifications (cam, intake, and exhaust manifold) that might help a little, but you won't likely save enough on gas to pay for them.
  • You are doing well with what you have. Don't try any of the gimmicky things like air filters and what not. They will either not help or not help enough to recoup the purchase price in mpg difference. The only other option to improve mileage is to get a diesel rig, but those come with drawbacks of their own, mostly in repair expenses and what not. Diesel engines tend to be more expensive to repair and maintain than the Ford modular V10 you have, which is a very good, smooth, efficient, powerful engine.
  • If you want to get a little better mileage, cruise just above the shift point to overdrive. You need to have enough RPMs to avoid lugging, yet not enough to use too much gas. About 300 to 500 RPMs over the shift point should be fine. If you find the RV hunting for gears, you need to increase your speed. For me (Honda Accord), I get my best mileage at 55 MPH (~1800 RPM). Your RV is likely different, though.
  • If you have a large clutch fan on your engine I would swap it out for a "flex" fan. It will slightly improve your fuel economy but don't expect much because you have a V-10. The flex fan will also make it quieter in the cab. All the previous comments are right on the mark especially the advice about the tire pressure.
  • Thank you for your comments and suggestions folks. I guess it was unrealistic to hope for a "silver bullet" solution but I thought I would give it a try. I am concerned about get rear-ended if I get too slow. Thought I would put up a slow moving vehicle sign or flashers to warn others.
    thanks again.
  • I might look into one step past Missileman's flex fan idea - I wonder if an electric fan setup might help some. You might check out some RV forums, but be warned that scammers sometimes pose as owners to advertise.
  • @Minnemike, have you seen the bumper sticker" "You may have the right of way, but I have a truck"? You won't be rear-ended. Everyone except an 18-wheeler would lose in that match. And then they'd have to pay to fix your RV. Your RV is big, broad, and heavy. No worries. Unless you use that Mercedes-Benz cloaking device.
  • Texases brought up a very good point that I should have expounded on. The electric fan will also work in conjunction with the flex fan if you decide to do that. If you travel in the desert at all then having both would keep the engine from possibly overheating.
  • If you are getting 10 - 11 mpg from a 23 footer, I would say that is doing quite well. We owned a 26 foot Class C motorhome with a 460 Ford for about 10 years and a 25 footer with a Dodge 360 for a year before that and got about 8 - 9 mpg with both. Slowing to 55 will result in better fuel mileage and is not a dangerous thing to do in my view. We drove many freeway miles at 55 and never got rear ended and offended no one to where we would hear warning horns or got evil looks except one time when a guy in a Volvo tried to crowd us over; it did not work for him. Just stay in the right lane. There is nothing surprising about a motorhome going slower than the speed limit; it is practically expected. The minimum legal freeway speed is typically 45 so 55 is well over that. Motorhomes are quite visible and I believed early on that it was a very safe way to travel. We traveled almost 50,000 miles in motorhomes without a safety problem.
  • The only other thing you can donis add a secondary overdrive unit. However the cost involved would be tough to get back in mpg. You can see if any of the programmers out there can get more mpg out if a v10, but all and all as other have said i think it's a loosing battle.
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