Oil change produces better mileage???

[charlybasset]

So I went for my 3000 mile checkup at 5200K and I told the service tech that my mileage has been progressively decreasing... down to 25mpg with mixed city and hwy. I told him that I heard that there was a fuel pump problem (that I read about as per the courtesy of all of you out there... thank you!) and he said that the main symptom of the fuel pump problem is evidenced by prolonged turning over of the engine before starting the car. (Mine starts right up... but I didn't tell him that)

Also, thanks to all of you, when my wife told me that "the car makes a weird grinding sound when I put the AC on, specifically, the Defroster", I remembered that this was a problem with a lot of V owners. I told the tech... and of course when I needed it to make the sound, it didn't. (We'll see)

Anyway, had the oil changed, etc. (checking out what I requested) and with my immediate next tank (filled up in NJ b/c it's so much cheaper there) I had 32-33mpg for mixed city and hwy driving. Whoa! Didn't change my driving habits too much, nor my wife. She was amazed as was I.

Of course I realize that the oil change didn't give me more gas mileage, but perhaps they tweaked some settings on the car's computer? Is that possible? Also, will it last? any thoughts?

[keanucosmo]

Any chance they disconnected the battery? I noticed a spike in my MPG when I changed to an aftermarket radio, and I disconnected the battery. I speculated that it reset the computer.

[Knightro2]

At such low mileage an oil change really wouldn't make a difference. When you get into a higher mileage (70k+) and you change oil and use an engine cleaner it will clean out the gunk and help out a little bit.

[marleyfan]

I actually experienced the same thing. The first tank after my oil change I got over 100km more on my tank than ever before. I don't think I drove any differently...but maybe. My second tank after the change went back to "normal." Not sure if there is a correlation between the oil change and the temporary increase or not.

[frankoV]

My mileage jumped after the first change as well . . . it will get better, they say (rout around the baord and you'll find it) after the break-in period that runs anywhere from 5000k to 50000k

I think that the change in weather made a big difference.

Disappointing to read that my mileage may go down next week after the second change. Here's hoping I'm OK.