Hello, I have a 2006 Saturn Vue FWD Base model with the Honda V6 engine and when I had it in Wisconsin, I consistently got 270 miles per tank. And now in Texas, I’m consistently hitting empty at only 200 miles every time. It seems like a pretty drastic drop when my driving has stayed consistent. Wondering if anyone else has had similar issues or has any solutions?

Some maintenance I’ve done to try and fix it but made no difference:
-Tried injector cleaner
-Tires are aired up and alignment is good
-No active check engine lights
-New spark plugs and coils
-When the O2 sensor went bad it was replaced and the battery was disconnected to reset the computer.
-The passenger side motor mount was bad and rumbled the engine but that was replaced also

Current Mileage: 134,000

 

Did you get your better mileage in the Summer? We have Winter blend fuel now with more Ethanol now and everybody's mileage is less.

 

It was consistent year-round up north at 270 per tank and ever since it came down here it's been terrible. I've tried different gas stations or running different octane levels all with the same result of being empty by 200. I'm almost positive it is 10% ethanol in both places

 

Are you driving faster in Texas, seems like they drive pretty fast there. Have you replaced the timing belt yet? If you get one cam a tooth off it could explain the mileage drop. Maybe the thermostat has lost its rubber seal and is letting coolant through all the time. This makes the engine run cooler and rich for a much longer time. Just floating some possibilities. .

 

I'll have to check the timing tomorrow. But I've also been driving about the same speeds and distance I always have and it sounds like it's running fine so who knows, I'll look into it. When I took it to Firestone at the beginning of the year to get inspected for the mileage drop and the O2 sensor I know they also recommended a fuel cleaning that's the only thing I didn't do. But I also read if it's not direct injection that's just a money grab.

 

Wisconsin in general is pretty cold. Lived in Madison for 7 years.

Texas is pretty damn hot.

Good part of it be that you are using the AC constantly done in Texas whereas it got little use in Wisconsin? I don't believe that would make up for that much of a difference, just thinking.

Stop and go versus traffic light free highway driving?

 

Wrong heat range spark plugs? IDK, just thinking outside the box.

 

Are you using the stock plugs called for in the owner's manual?

thoroughly unrelated yet related, I tried to help a friend reinvigorate an early 2000s BMW 325i. It had some serious running issues, so instead of putting genuine BMW spark plugs in it, we used to cross reference chart and got something else, assuming when we were done diagnosing and fixing it we would switch the plugs to the good ones. We finally got it started on The test plugs.

We were so happy it started that when it tried to idle and ran like complete crap, it took us two days to remember/learn that we had never swapped the real plugs in. BMW plugs in, 90% of remaining running issues gone.

I know you say the vehicle runs well but the gas mileage is down. Per Rube's statement, I'm sure we were at least two heat ranges off on the BMW. You may be one. As a further example, the Saturn S series is very picky in general about spark plugs and runs best on only the cheap copper plugs. Not iridium not Platinum.

Being a Honda engine, I'm sure they have something spec'd out quite precisely for that engine. If you're not already using it I suggest doing so.

 

The only thing is it was still having the issues with the same spark plugs it was getting 70 more miles out of so I highly doubt it could be that. And I don't run the AC that often so it's not that. I have a feeling like the most probable thing right now is the timing belt may have slipped a tooth since it never got changed at 100k

 

So to be clear, it displayed issues with the plugs both before and after they were changed. If the plugs that were in there were past their prime, they would have eventually started degrading the mileage.

Apologies for the non Saturn reference, but my wife's 14 escape lost 4 miles per gallon on the same exact drive to and from work as the plugs hit their limit about 20,000 mi sooner than expected.

If the replacement plugs are not correct, it may be a coincidence that the new plugs give crappy gas mileage equivalent to worn out proper plugs. Probability? Don't know. Probably low. But in order to ensure as many things are correct, I'd still put the proper plugs in if they are not already in. It reduces the mystery by one variable, which is one more than before.

Indeed, if the timing belt didn't get changed, it's entirely probable that the engine is out of time.