Thor Forums

[Chance]

Engines have a sweet spot, or more accurately a sweet area of performance at highest efficiency if we are more realistic, but that has to be balanced against vehicles requiring less power as they slow down. When it comes to MPG, there is no speed that can yield a sweet spot just because it’s a V10. It doesn’t work that way.

The same V10 may maximize MPG at 45 MPH in one motorhome, and 55 MPH in another motorhome. And even that is affected by driving conditions beyond speed.

My highest MPG on the many motorhomes with V10 I’ve driven have always been at the slowest average speed for that tank of gas. That applies to my Class C, rentals, or present van.

I know based on technical education that there has to be a low speed at which MPG starts to drop off because it’s too slow, but I honestly haven’t come close to that speed yet because it’s so slow that I don’t have the patience to drive that slowly, even if it were safe (and it wouldn’t be most of the time).

My highest mileage gains were when sight seeing at low speeds for extended periods. And they were often at high elevations where air is thinner, which can also improve fuel economy (MPG).