fuel
94 chev 454 TBI OD Trans class c 25 FT runs great gets 9mpg always used reg gas lately with 10% ethanol.Is the ethanol going to mess up my good running RV. Have noticed that mid grade gas often has ...
Forum Discussion
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?
