Wednesday, November 30, 2022


Tips for better fuel economy, especially for Class A motorhomes


RV Tire Safety

with RV tire expert Roger Marble

Smartway is a program from the EPA that is supposed to help truckers select tires that have better Rolling Resistance (the way tires can be measured) for better fuel economy.

Review the information provided at the above link and you will see that most truck/bus tire companies have a line of tires available that meet the Smartway standards.

Will selecting one of these tires get you 20 mpg on your 40-foot diesel pusher? No, it won’t. But it might get you a 5% improvement, which could be like getting $0.15 off a gallon of fuel – which I bet anyone would like.

While we are on the topic of fuel economy, here are some tips:

  • Every 2% reduction in aerodynamic drag results in approximately 1% improvement in fuel economy.
  • Above 55 mph, each 1 mph increase in vehicle speed decreases fuel economy by 0.1 mpg.
  • Worn tires provide up to 7% better fuel economy than new tires.
  • Ribbed tires on the drive axles provide 2%–4% better fuel economy than lugged tires.
  • Every 10 psi that a tire is underinflated reduces fuel economy by 1%.
  • Tires make the biggest difference in mpg below around 50 mph; aerodynamics is the most important factor over around 50 mph.
  • The most efficient drivers get about 30% better fuel economy than the least efficient drivers.
  • Idle time is costly. Every hour of idle time in a long-haul operation can decrease fuel efficiency by 1%.


Read more from Roger Marble on his blog at

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Tommy Molnar
3 years ago

“Worn tires provide up to 7% better fuel economy than new tires.”

Now THIS, is interesting.

Bob p
3 years ago
Reply to  Tommy Molnar

A new tire has deep tread that squirms under load making it more resistant to rolling, as the tread wears down the tread doesn’t squirm as much therefore it rolls easier. Low rolling resistance tires have less tread depth than standard new tires so less squirming. You get less tread depth but better mpg, and unlike truck drivers, most motorhome owners tires go out of date before they wear out. If a truck driver gets 5-7% better fuel economy driving 125,000 miles per year he/she will save enough money to buy new tires more often.

3 years ago
Reply to  Bob p

Whodathunkit? Good info here. But you also have to consider the trade off’s of less tread like maybe increase risk of hydroplaning, traction in snow and cornering, etc. I always wondered how “low rolling resistance” tires achieved better mpg’s.

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