I hope someone can tell me if what my dealer is telling me makes sense. Sorry it's long.

I have a 2009 Fit (23,000 miles so far) and last week while driving, check engine light came on. I took the car to the dealer to get it checked out and they told me they just had to clean something and that it was fixed.

Well, the next day I picked up the car, the light came back on again so the car went back to the dealer. And I noticed that the gas mileage was really bad. This time, they told me they are not sure what is wrong with it and that they are calling the Honda. Then they updated me and told me that they drained the gas from the car since they think using different gas types (like going from 87 to 100 gas) might have something to do with it.

They called yesterday and told us that the car is fixed. However, we have to use 100% gas from now on.

Now, I do not understand why. I mean the manual does not say that Fit requires using 100% gas only and gas stations with 100% gas are not very accessible where I live. How can gas types affect engine or performance? Does this mean if I go back to using 87 gas, the engine light will come back again? Will it adversely affect the car? This never happened with our other cars before and I am highly confused and annoyed.

Thanks.

 

Did they pull a code and if so what was it? If not then ask them to and post it. IF it comes on again then run over to an Autozone and they will read the code for free.

I have had 0 problems going to different types of gas and run 87 for the most part. Maybe you got BAD gas and I would check with the last station you filled up before having your issue. They may have gotten reports from others. It may help narrow down your problem.

 

The numbers you mention 87 to 100 aren't % values. They're octane ratings and I've never heard of 100.

87 should be fine. It sounds to me like you got some bad gas. Don't fill up again at the last place you got gas.

 

Thanks for replies. I'm not sure about the bad gas though. I used 87 and then used 100 gas then went back to 87 when the tank was about quarter full. After 2 days, that's when the check engine light came on. Could it be the combination? Thanks!

 

Does not sound like it would cause a problem.. Maybe you have a loose or bad gas cap.. If loose it can take a bit of time to clear. If bad it will cause on going problem (CEL). Bad gas can cause bad performance/mileage and will do so until run out of system. Good that they drained it. Get the code.

 

Don't know what they mean by 100% gas either. There's no 100 octane gas sold at regular gas stations. The marketable range is 87-93. anything over 87 is OK.

Were they talking about not using gas that has ethanol? Ethanol is OK, up to 10%. It would be hard to find a station that sells '100% gas' (no ethanol).

It's certainly not a problem changing octane or mixing different blends/brands.

Think you got some bad gas.

 

Hope you didn't put some aviation fuel (Avgas) in your Fit. That's the only thing I can think of that has 100 octane.

 

Sounds like it was E85 which has an octane rating of 100-105. E-85 has about 70 percent ethanol in it and would cause that problem. I would change the fuel filter too because there could of been a lot of settlement that would plug it, and make your fuel pump work harder and the pump will go out when you least expect it. Sounds like the dealership cleaned that but make sure. E10 gas is every where so finding 100 percent gas is going to be impossible. If they came out with E15, Your car would run lean, but would eventually adjust to it.

100 octane racing fuel needs a fuel air mixture of 13.7 to 1 to burn, compared to 14.2 to 1 with E10 gasoline. It would run leaner but would have ran OK in the engine with no problems.

 

some great answers in this thread.

 

DITTO
I'll ask ny111 who's gas ya buying? And WELCOME to the forum.

 

Well, I picked up the car yesterday and no more light. But they still insisted that the light came on because of ethanol and therefore I should only use ethanol free gas, which is very unrealistic.

Oh, I was very confused about the whole 87, octane, ethanol, etc... Sorry for confusing you guys too. And thank you for enlightening me

I do think I got a bad gas from the last fill up, it was a gas station I never went before and the problem started since then.

So for now, we are going to use ethanol free gas for the next 2 tanks and then go back to 10% ethanol and see what happens.

The code they pulled up was 0171 if this means anything.

 

P0171 = Fuel System Too Lean (Bank 1 or 2)

Symptoms

• Check Engine Light will illuminate
• In some cases, no adverse conditions may be noticed by the driver
• In other cases, there may be performance problems, such as a lack of power on acceleration and some "coughing" or misfiring
• The vehicle may have trouble idling, especially when warm or when sitting at a stoplight

Common Problems That Trigger the P0171 and P0174 Code

• PCM software needs to be updated
• Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.)
• Mass Airflow Sensor (MAF)
• Plugged Fuel Filter or weak Fuel Pump
• Plugged or dirty Fuel Injectors

I'm still leaning towards Bad Gas. I've seen this when a friend got gas from a station that was draining the tanks so they could be replaced. He was one of the last and got a bunch of crap that clogged the filter causing the lean condition.

 

Im wondering if you filled up with E85 by mistake and not regular gas. That or like others say a bad tank of gas

 

Ethanol free is making a come back, The mechanic is right. Hard to find though. Here is a link to ethanol damage to our cars Engine Damage, Driveability & Performance Issues Due to E10 Gasoline.

 

bad gas comes with or without ethanol.

Ethanol isn't the cause of the problem. Water in the gasoline could be. Ethanol, as we all know, holds more water in solution, so it would actually help keep water phase separation from becoming a problem.

Here's a paper with references on the EPA's website concerning the topic if you're interested. link

 

At what temperature does water fall out of ethanol? Premium gas also has lower amounts of ethanol 5.5,7.7,10 percent for regular.
Ethanol is corrosive, it also picks up water, can not be put in fuel before it loaded in the tanker and cant be shipped in underground pipelines. Hydrogen is the most abundant element and oxygen is everywhere too. So I agree that water is an issue.

 

Please provide a source stating premium has any less ethanol than regular. I haven't found any.

Ethanol does absorb more water than gasoline. That's why the product HEET uses it to "dry" gas (your post).

Fuels with ethanol are less likely at any temperature to have phase separation. My link. Check pages 2 and 3. Pure gasoline will phase separate before gasoline with ethanol. The data show that gasoline with ethanol tolerates water (remains in solution) down to about -30F, but gasoline alone separates way above 0F. Maybe this is why HEET sells its product. Maybe this is why it's called HEET. What do you think?

in quantities less than 15% it's not considered corrosive (in today's cars). In greater quantities the car must be built for it (flex fuel cars).

you got me there.