I just had my first oil change. Had the dealer use the 0W20, no idea what brand they used. They also did the recall computer upgrade. My mileage took a serious hit. They did lower the tire pressure but I put it back to 45 psi. I had been getting about 50 mpg, now it is more like 44 mpg. The weather has turned colder, from around 60 in the morning to 35 or so. I does take a lot longer for the engine to warm up and my commute is short. I am curious if the weather accounts for the change or does the computer upgrade make the difference.

Any thoughts?

Clay

 

Clay, do you mean you cleared the MPG meter AFTER you got the upgrade, and you dropped to 44? Or does the tank you are measuring include the time when they had the car for the upgrade?

What I mean is that the upgrade involves them letting the car idle for about 20 minutes. I took mine in just after a fillup and I had 70 MPG on the FCD after about 3 miles and when I got it back it was on 24 MPG and 5 miles. Then later I saw someone post that the upgrade involved idling for 20 minutes, and the mileage drop made sense.

As additional info, my car has shown no negative effects from the upgrade - MPG is not higher or lower.

Hope this helps........

 

I had the upgrade done a few weeks ago..... I notice some small changes in the cars behaviour, but nothing significant. However, a drop in temp will definately make a noticeable drop in mpg. (It's even worse <much much worse> when it rains...)

(The biggest change from the ECU update I notice is when going downhill right after starting the car from being cold... before the upgrade, it would peg at 120mpg whilst going downhill cold. Now it won't go over 30 or so in the same circumstances. Is the upgrade trying to reduce emissions by warming up the engine faster?)

 

I reset one of my trip odometers aftert he upgrade and that is the mileage I was noting. On my commute, I typically would get 50 mpg. Now the same trip yields 44 mpg. Exactly the same trip and same conditions except temp and the service work.

Clay

 

My guess is that your drop has to do with the normal winter drop - modified fuel, longer warmup time, etc.

I don't think there is a history of people who have noticed MPG drops after the recall upgrade.....

 

I had my upgrade done last June at 5000 miles along with my first oil change. (to 0w20 mobil 1) my mileage went up most of the summer- probably due to temps, because it sure is crashing down now!
I think your mpg hit is due to winter temps and not the upgrade. I have a home office and do mostly local short drives- the car never gets a chance to warm up and I've gone from high 50s, to struggling to hold high 40s in mpg this past month. very frustrating.

 

I had my upgrade done last weekend. Only a about 140 miles since I had it done but it feels like a slight mileage increase, who can be sure though. It may have been the wind was in my favor going home, maybe the earth was spinning faster, maybe I was drafting and didn't really notice it - I don't know.

What I do know is I bet it's the weather, my Insight has taken a HUGE mileage hit this week. Don't have the heart to break out the HCH and kill the mileage on that tank too since I have been doing excellent so far. (excellent for my area, 56.7/around 350 miles)

 

That cold front that came thru made all the difference. I can hit 65-70mpg during the day when it is still pretty warm but at night in below freezing temps the car has trouble hitting 60mpg.

 

I feel the difference even in my relative temp drop. 55 degrees may not seem bad but it's a good 30 below the highs all last week in Jax, probably with pretty similar effect as many of you who went from 50 to 20, only I get rain instead of snow.

 

i HATE what my snow tires are doing to my mileage! and the worst part is, after our blizzard false alarm last week, there's no sign of the nasty white stuff in the forecast. i could just as well have left them off a while longer. i don't know what it is (probably global warming) but our winters have been strangely devoid of snow lately. i remember a halloween blizzard a while back that dumped 31 inches on us. it started as rain, and then froze and snowed. the roads were like washboards for a week before they were totally clear. it actually shook the muffler off the honda accord i was driving.