My Suburban has the flex motor and i was wondering if it is worth using E-85 fuel. Do you get better gas mileage. The fuel is about the same price as gasoline. Just looking for everybodys 2cents.

 

you get worse gas mileage actually. It has a lower energy density. The epa estimate for the distance on one tank was substantially lower on our flex fuel suburban.

 

I have used E85 a few times in my tahoe. Regular MPG 15-17. E85 MPG 12-14. You can do the math. The tahoe runs good on it and have no complaints but it isn't a cost savings thing unless you can get it about 50-60 cents cheaper. I think I figured I had to get it for about 20%-25% less to break even. At 1.80 gas and 1.50 e85 it was ok but now it is 2.59 gas and 2.29 E85. That actually looses me money. I would say try it and see what your MPG is maybe yours won't drop as much. Performance doesn't drop at all. If anything I think it ran a tiny bit better due to the high octane.

 

sure, it supports us WI corn farmers, plus the stuff smells great when its burning.

 

I have always wondered how the flex fuel trucks ran. It makes no sense to have flex fuel be as expensive as regular fuel, but gets worse gas milage. What was GM thinking?

 

GM doesnt set the fuel prices. Its really an act of good faith. It makes some people feel all warm and fuzzy inside to know that their vehicle can run a RENEWABLE energy source. The fact that few people actually do doesn't make a difference.

 

it takes next to nothing to convert a regular engine over. Its basically a certain type of rubber seals since the ethanol will eat stock ones....that and any alunimum that the fuel touches has to be anodized since it will corode, not really a problem if the fuel is only run on ocation or only a 10% blend. Its a marketing thing, change a few orings and you have more selling points. I'm sure corn farmers (some ppl use trucks for actually hauling things besides *** like most of us in here do) would buy an ethanol ready truck over one thats not.

 

but if it has the higher octane has anyone tried turnning up the timming a little to take andvantage of it and maybe that will help the mileage as well?? just a thought

 

I don't have personal experience but I have read were some turbo ricers running large injectors and fuel management computers have done this. They were running exclusivly on E85 and getting quite a bit more out of their car. I don't think a stock truck would have quite the benefit but I would be curious if anyone with a tuning software has tried it. How bout the guys going FI? Would be an interesting test but on these large motors you may have trouble getting enough E85 in the motor if you were putting up high HP. Need like 50% more fuel or something like that to get the right A/F mix.

 

why would you have to have so much more fuel?? but yeah that would be a good test hell if it worked good and you could crank the boost up some more i'd try to convert mine myself.