Hi all,
I noticed the last 2 filled up, mainly used Costco's gas, 91 oct, my mpg dropped from avg 26-27 down to 23-24. My fuel light dont usually come up until 365 miles, but now it light up around 340. I know it is not a lot of difference, but wonder if anything I should be checking. Air filter is not bad since the car only have 9700 miles. Tires pressure are 33 front and 32 rear. Is there anything I should be checking or should fill up couple more tanks and see the result? Beside the temperature is a little bit colder now (socal weather lol), driving habits, routes and distant are the same.

Thanks,
Danny

 

Gas refineries change over to their winter blend to deal with the colder weather. In Massachusetts, I've always seen a drop in MPG over the winter months. Depending on where you are this is probably the reason you are experiencing this.

 

I've heard of that but never really having issues with my past cars here in southern cali.

 

Winter vs summer gas?

 

I guess so! Thanks all. I want to make sure nothing is wrong so I don't have to bring the car in. Although I did noticed the transmission is acting up more this past 2 weeks, shifting isn't as smooth as before, pretty rough actually. its also delay shift like the V6 tranny that most people here described.

 

yeah it's normal to see a drop during the winter months. My average dropped from 32 down to 30 and this last week were the temps are in the upper teens I am managing 28 over all

 

Thanks all. Not sure why my past cars does not experience this but this one does =( I guess I will have to learn and deal with this hahaha

 

Don't want to confuse the issue, but I've lived in Southern California for 50 years and have never seen a noticeable difference in mileage from one season to another. There probably is some, I've just never noticed any.

Could your driving style or commute have changed? Driving at different time of the day (temperature)? Costco had some bad gas?

 

Well, seasons don't change in Southern California, so it might be one of the worst places to use as an example. I assume they change out summer and winter grade gas there, but you get perpetual summer.

I have no idea what's causing the difference in mileage the OP is experiencing, but contributing factors could be the grade change and also the cold weather and maybe differences in how you drive in cold weather. Do you idle more to warm the car? Do you run the heat or defroster more which under some conditions could influence mpg.

 

I only posted because the OP said he was from southern California. I wasn't using it as an example.

We do have summer/winter blends here (the refineries love it, they can gouge us more), but other factors are probably influencing the OPs mileage more. Probably no big deal in any case.

 

I been driving since 2002, and never see the difference between seasons. On my 2013 Accord, I used 87 at Costco and there is no different between summer or winter. On my old Accord with H22a, I used 91 at Chevron and Shell and there's no different either. Maybe 91oct at Costco does effect the mileage and not 87oct?

wlkeel,

My driving style, distant has not change. I usually warm my car for a minute before head out each morning. I'll try to use different gas location and see if there is any differences. The last 3 refilled I noticed the mileage differences and my transmission is acting up more than summer. Maybe it just the car itself hahaha.

 

I have noclue (pun intended) as to what is going on. I'd continue to monitor it and perhaps mention it at your next service.

By the way, the 8 sp DCT shifts a bit more pronounced when it's colder and before it's warmed up. However, I doubt if this is a contributor to any significant mileage differences. Hasn't been for mine.

Anyway, good luck with this.

 

Thanks wlkeel. My transmission does act up a lot more since I noticed the issue. The "feel like being rear ended" when come to a stop happened more often than before, but not consistent enough to show those tech at the dealership. I already tried with the service adviser, and as expected, their response is "maybe it's the way you drive" blame game crap. I'll see what happen when I change to a different gas, although I heard all location are the same hahaha.

 

winter gas and the air density is increase so your car use more gas to maintain that 14.7 air fuel ratio

 

I guess so...it is suck to see this on the Acura and not on the Accord hahaha...