E85 flex fuel questions – page 2 – survivalist forum gas number density

Unless you have a high compression engine you are wasting money running higher octane grades of gasoline. Higher octane gasoline is harder to ignite. If you run it you need to run a higher energy ignition system. It contains no more energy than other grades of gas. You will only see a power boost if you retune the control system to take advantage of it, after you boost your compression ratio and change valve timing.

The reason consumer fuel pumps peak at E85 is the 15% gasoline helps the alcohol to light in a road engine. Even with the monster drag race engines that run on pure alcohol you will see the crew squirt gasoline in the butterflies when starting them.

The only gas vehicle I now have, yes even both cars are diesel, is a Flex fuel 5.3 Vortec powered 2002 Suburban 1500. On 87 octane it gets 16, on 93 octane 14, and e85 10 MPG. If I run three tanks in a row of e85, giving the ECU time to adjust, it will bump up to 11 MPG. There is no difference in performance other than the lower economy. There has been only one station within 30 miles that sold e85. They sold it for 9 cents per gallon less than 87. For me also it makes no economic sense to run e85. In comparison, the Cummins in the 4X4 DRW get 15 mixed city/highway. It gets driven more than the Suburban these days.

If I want to contribute to saving the planet I’ll keep using the diesel Cruze which gets 30+ city and 50+ highway, has auto stop technology making ZERO emissions when sitting at the lights, and puts almost no particulates out the exhaust at WOT.

Unless you have a high compression engine you are wasting money running higher octane grades of gasoline. Higher octane gasoline is harder to ignite. If you run it you need to run a higher energy ignition system. It contains no more energy than other grades of gas. You will only see a power boost if you retune the control system to take advantage of it, after you boost your compression ratio and change valve timing.

The reason consumer fuel pumps peak at E85 is the 15% gasoline helps the alcohol to light in a road engine. Even with the monster drag race engines that run on pure alcohol you will see the crew squirt gasoline in the butterflies when starting them.

The only gas vehicle I now have, yes even both cars are diesel, is a Flex fuel 5.3 Vortec powered 2002 Suburban 1500. On 87 octane it gets 16, on 93 octane 14, and e85 10 MPG. If I run three tanks in a row of e85, giving the ECU time to adjust, it will bump up to 11 MPG. There is no difference in performance other than the lower economy. There has been only one station within 30 miles that sold e85. They sold it for 9 cents per gallon less than 87. For me also it makes no economic sense to run e85. In comparison, the Cummins in the 4X4 DRW get 15 mixed city/highway. It gets driven more than the Suburban these days.

If I want to contribute to saving the planet I’ll keep using the diesel Cruze which gets 30+ city and 50+ highway, has auto stop technology making ZERO emissions when sitting at the lights, and puts almost no particulates out the exhaust at WOT.