does anyone know if an 09 hhr can have the e85 equipment removed and the car converted back to a non-e85 vehicle. my mileage is terrible and e85 costs so much that the further loss of mileage from using e85 ends up costing more than non-ethanol gas. if i could just get close to the rated mileage of a non e85 hhr i would save quite a bit of $.

 

you don't have to use e85 it's just an option, you can run regular gas no special equipment needed

 

Yeah..... If it's a "FlexFuel" vehicle just use Gasoline and the engine computer will adjust. (That's what the "flex" is all about) It should all be described in the manual if you have one.

It may take a tankful or two before you get any accurate numbers though.

 

x 2, run a tank or two of normal gasoline through it to purge the remaining E-85 and you're good to go, it will adjust to the new fuel and your mileage should improve.

 

i did use e85 for a while. terrible mileage and more cost. so i quit using it. if e85 cost less it might be ok, but it doesn't work out cost-wise at current prices. my problem is that even the mileage with gas (after many tanks) is nowhere near ratings. i consistently get less than 24mpg on hwy and easily 5 mpg less than ratings in mixed use. i just wondered if the e85 equipment might be compromising the mileage. i know the ratings are just averages so maybe i got a car on the low end of mileage. at any rate, i will probably need to sell the hhr if i can't improve the mileage. i like the car a lot, but not not enough to keep paying for the extra gas.

 

Give it a while to adjust. It takes a few tank fulls for the computer to compensate. I have the E85 Flex fuel 2.4L and I tried it a few times. Once I decided it wasn't working out I went back to regular gas and it took a few tanks to adjust. I usually get between 29 and 32 now consistently.
The mixed use you spoke of isn't helping either. Mixing E85 and regular gas will no doubt result in lower milage than and non mixed tank of regular gas.

 

Something is wrong if you are only getting 24 MPG on the highway with "regular" gas. Mid and super should give a little better than regular, but not enough to be economical (unless you have an SS). In most ,not all, of the country gas at the pump is 10% ethanol. Most places I've seen E85 is about 20 cent a gallon cheaper than regular, but the MPG makes up for it.
I thought that the only difference between a "normal" and a "flex-fuel" was the gaskets and rubber bits that come into contact with the fuel. How does the computer sense the type of fuel? I.E.: What if I put diesel fuel in the tank (STP/SeaFoam/Texaco etc. fuel injector cleaner), would the computer sense it and compensate? Just pondering.

 

The ECM in a FlexFuel vehicle is sent a signal from a sensor in the fuel tank which identifies the fuel on board using a measurement of the specific gravity of the fluid in the tank. This information is then used by the ECM to adjust ignition timing and other variables allowing the vehicle to run on E-85.

When using something like an injector cleaner or SeaFoam, the amount of fluid added to the tank is diluted in the fuel already present and its not an issue. Please don't attempt to run anything but regular gasoline or E-85 in a FlexFuel vehicle as severe engine and fuel system damage will occur.

There is no practical way to remove any FlexFuel components from an HHR without removing the entire fuel system and engine control system, I'd suggest the OP take the vehicle in to his dealer and have it checked over and possibly re-flashed to ensure that its running correctly.

 

When you "switched back" to regular gas and were seeing only 24mpg highway did you do these things.....

First run several tankfuls of gas (don't switch back and forth and/or blend as you can't make any determination that way)

Second, after several tanks. Get on the highway, RESET the MPG reading on the DIC at 55-65 mph for 30 miles or better of consistent speed. What kind or reading do you get? 24MPG? There's no way it could possibly be that low unless you have major problems. Now track this reading through several tankfuls without going back to grain.....

Third, check the MPG reading on the DIC against actual usage after several tanks (keep your receipts/mileage/gallons, and do the math.... most people find the DIC is actually reading low..... in other words DIC says 28mpg average actual is closer to 30.

I'm not suggesting you drive around just to burn up gas..... several of the times I mentioned "tankfuls" overlap (The second and third step above) Also many people go through a tank a week or so and there's no need while doing this to empty the tank.... just do your usual, but don't add any FlexFuel and do that RESET deal I mentioned.... this process should only take 2-3 weeks for most people.

Your numbers should look better to you.

Now @ donbrew.... The 2.4L is designed for premium also, not just the SS, and can get better enough mileage to make it worthwhile running it.... Depends on your driving habits. With the recommended 93 octane it gets the full amount of power it's designed for, with 89 or 87 it's scaled back considerably by the computer to adjust for the lower octane...... causing you to push it harder (if that's the way you drive) which nets in lower mileage. It's been well over a year since I did the math on mine but I still use only 93 as it was that much different. It nets me my best MPG for the way I drive.... Others here have noted the same thing.

 

Yes, then the engine would implode in a second. Everyone knows you can't run diesel in an engine not designed for it and visa versa.