[npaggett]

Wow.

I knew I was going through this tank faster than I thought I should. I tracked my mpg for the last three tanks...I'm currently averaging 24.8mpg. I drive 10 miles each way - all highway. I am between 60-65mph the whole way. I probably add another 10 or so miles at 40-45mph once a week.

Before the last few tanks, I was at around 30mpg. I'm not using the A/C anymore than I used to, I'm not idling the car. Nothing has changed in my driving habits. It got real hot for a few days but has stabilized.

I guess I'm just floored. I expected much better than this. Heck, with my old HHR I got 22mpg even with A/C on and city only driving.

My car is a 2013 Cruze LS. I use 87 octane - no ethanol.

 

[npaggett]

I would agree to change except that I've been running 87 for three months and this plummeted out of nowhere. THAT is my primary concern.

 

[npaggett]

What has your weather been doing? Is your car parked in the sun? If your weather is anything like the weather here the temps have been 80+ degrees daily and if parked in the sun the car is easily 120+ degrees.

There is also the chance you got some bad gas.

It has been in the mid/upper 80s but again...that isn't that different than what it was when I was getting better mpg. And no, I don't park in the sun - at work we have a garage and at home I have a cover.

Do you fill up at the same station all the time or hop around? I've gotten some tanks of bad gas before, and fuel economy did drop like a rock.

I always get gas at the same place. Three tanks in a row of bad gas seems really unlikely, doesn't it?

Could there be a mechanical issue causing this?

 

[npaggett]

Have you checked your tire pressures lately? Did you hit anything that might have thrown the alignment off? Are you carrying more cargo/passengers than you used to?

Another thing is that your E0 gas got diluted down to E10. That would cause a drop in fuel economy.

I check my tire pressure regularly (I am compulsive ever since last summer when a tire blew out on the freeway! eek!) and they are consistently at 38. I haven't hit anything but I have noticed a slight drift to the right...

And my gas is E0 year round. Around these parts we have gas stations that are "100% gas" and never add ethanol.

And the only additional cargo is about 10lbs of books in the backseat. I would be sorely disappointed if that is what caused this..I mean...10 lbs! haha

 

[npaggett]

Get an alignment (slight drift to the right). Also, were you running the A/C before you noticed your MPG drop and are now running it?

Yep, A/C has been running the whole time. I'm a wuss when it comes to heat.

I just noticed the drift for the first time the other day...I thought maybe the road was angled (common around here) but on my drive to the store it did it again. I'm kind of ticked that the car needs an alignment at 3,300 miles. I haven't had a new car before...is that normal?

 

[npaggett]

Yea, the roads I drive on are all great, so that wouldn't explain it. Ugh.

And again, while I get that short trips lower mpg what concerns me is that this was the same way I was driving before, and my mpg suddenly dropped by around 5. That seems concerning.

 

[npaggett]

If that is really happening at 3,300 miles I am going to be ticked. 20 miles a day is not that unheard of. I have driven plenty of other cars just like this and NEVER had my mpg drop in this manner.

And, for what it is worth, I drove it 50 miles last night with an average speed of 68mph...I got 24.3mpg.

 

[npaggett]

That was actually with a different gas station. I had to fill up before the trip.

I love this car, I do, but I am really irritated as to why the mpg dropped so far so quickly. Ugh.

 

[npaggett]

How are you calculating the MPG? Are you going by the DIC, or by miles traveled divided by gallons in?

I use both. My DIC is always within 1/2mpg from my actual calculations.

You never did mention where you happened to find no ethanol 87 octane. See one thing about filling at no name stations they buy their gas from the cheapest place they can so you will never get consistent quality. What you might be experiencing is gas from one of their crappier suppliers. At least with top tier or a name brand that should not be an issue.

I would also not be using no ethanol 87 octane in anything other than a lawn mower and this is coming from a guy who runs 91 octane no ethanol 99% of the time. See once the temperature is above 85-90 I switch to 89,90 or 93 octane with 10% ethanol for the better high temp knock prevention.

What engine temps does the 1.8L run? Is it as hot as a 1.4T? Suspect that low octane with no ethanol runs like crap when its hot.

Sorry, never saw the question

Most of our stations down here have at least one line of pumps with no ethanol gas. I get mine at a Shell station a block from my house.

I disagree about not using 87/0% ethanol. I have always used this and never had a problem before. There has been no benefit shown with higher octane in this engine and considering the cost per gallon difference here I would have to get a significant increase in mpg to justify the higher cost per gallon. That just has not been shown to happen. Keep in mind right now my 87 is $3.14/gallon; 89 is $3.35/gallon and 91 is $3.55/gallon.

 

[npaggett]

So, I had to make a big trip this weekend. Heading out I used up the last of this tank (got 24.3mpg overall). Coming back, I filled up with 93 and drove 269 before I had to fill up. Took 12.1 gallons to refill. Average speed was 66mph - all highway driving. That is about 22mpg. This is getting worse. I'll be calling the dealership tomorrow. It seems it gets worse with each fill up.

 

[npaggett]

Thank you, I've been asking this whole time if there might be a possible mechanical issue and all I got was a bunch of lectures about the gas I use. Clearly, the gas I use is NOT the problem.