fuel

Ethanol is only a problem when something sits unused alot and also todays gas formulations deteriate faster even without ethanol than they used to. If you drive regurly dont worry be happy.

Golden_HVAC wrote:
I found that I get better mileage with 91 octane gas on all my fuel injected engines that have ping sensors.

Your engine has ping sensors and Oxygen meter on the exhaust. The system can advance the timing to make more power from a given amount of fuel, except if it detects pinging from bad fuel, it will retard timing and enrichen the fuel mixture - making fuel mileage take a dump if you use bad quality fuel.

Advanced timing with 91 octane fuel is possible, improving fuel economy without pinging due to the higher octane fuel. The computer will do this automatically, but it might take two tanks of fuel before the computer fully realizes it has better fuel.

I was getting 8.8 MPG with my motorhome while running 55 mph and 91 octane Chevron gas - compared to getting 7 mpg with regular gas and driving 62 - 65.

So try it. I figure if I was getting more than 8% better mileage, then it is worth spending the additional 20 cents, or 5% more in gas cost.

Fred.

I agree using a higher octane gas can improve gas mileage but you also changed the speed you drive. What portion of mileage increase was due to the gas and what portion due to speed change?

Yep, that e-10 really messes up all these fuel systems for sure !! That's why you see all these RV etc etc etc parked along side all the roads all over the place !!
Why don't you whiners get a life ???

Watch your rubber fuel lines very closely for softness and leaks.

I found that I get better mileage with 91 octane gas on all my fuel injected engines that have ping sensors.

Your engine has ping sensors and Oxygen meter on the exhaust. The system can advance the timing to make more power from a given amount of fuel, except if it detects pinging from bad fuel, it will retard timing and enrichen the fuel mixture - making fuel mileage take a dump if you use bad quality fuel.

Advanced timing with 91 octane fuel is possible, improving fuel economy without pinging due to the higher octane fuel. The computer will do this automatically, but it might take two tanks of fuel before the computer fully realizes it has better fuel.

I was getting 8.8 MPG with my motorhome while running 55 mph and 91 octane Chevron gas - compared to getting 7 mpg with regular gas and driving 62 - 65.

So try it. I figure if I was getting more than 8% better mileage, then it is worth spending the additional 20 cents, or 5% more in gas cost.

Fred.

How much more per gallon is mid grade vs regular grade?

Ethanol also results in lower mpg....so you fill up more often/spend more

Ethanol screws up pretty much any fuel system made before about 2009 so yeah probably.