15% reduction in MPG after 1st oil change
 

I just had my oil changed. Cost was $45+ tax. (They wanted $40:angry: for Tire Rotation, but I passed on this).

I was working on 47mpg tank, but at oil change, my trip meter was reset (by product of clearing service wrench?).

The second half of the tank after oil change, I averaged 41mpg over ~200miles.:angry: The drop in mileage doesn't compute with me - Maybe breaking in new oil causes mileage drop...

Anyway, I am on a new tank and am back to 46mpg.:shade: Maybe it was just an anomoly.

Did anyone else experience something like this?

Re: 15% reduction in MPG after 1st oil change
 

Nope. Didn't happen to me, and I've never heard that. Maybe you were driving a bit differently, or in slightly different conditions? Could anything else have changed? If anything, it's counterintuitive that the mileage would drop after an oil change.

Re: 15% reduction in MPG after 1st oil change
 

New oil usualy increases mpg not lowers it.

Re: 15% reduction in MPG after 1st oil change
 

I thought it was strange, too. Same driving pattern - if anything I spent more time on Freeway.

I even checked tire pressure to see if the mechanic had lower it to spec, but that wasn't the case.

Anyway, back to normal.

Re: 15% reduction in MPG after 1st oil change
 

Where did you have your oil changed maybe they used the wrong viscosity?

Re: 15% reduction in MPG after 1st oil change
 

Actually, I also noticed a slight drop for the first tank following the oil change. And I did the change myself so I know it was done right.

Like you, after a few hundred miles it was back to normal. Several tanks since and I now have an improvement in mileage. But that's because I'm still learning how to drive this dang thing. It's more fickle than my wife.

Ron in SoCal

Re: 15% reduction in MPG after 1st oil change
 

I got it done at Honda dealer in Silicon Valley (Can I name the dealership?)

After 300 miles, my mileage is better than average (48mpg - 50miles into tank).

Maybe, draining oil and refilling leave some spots that doesn't get lubricated for awhile?

Here is my observation:
6 miles - 8400 miles -- 44-45mpg
~8200 - 8400 miles -- 46mpg
~8400-8650 miles -- 41mpg
8650 - 8700 miles -- 48mpg..

Interesting....

BTW, I will be making a road trip to Long Beach, CA from San Jose next week.
I'll report afterwards.

John

Re: 15% reduction in MPG after 1st oil change
 

Have you checked the oil level? Make sure they didn't overfill it.
That will hurt your FE.

Just a thought.

Regards,

Re: 15% reduction in MPG after 1st oil change
 

I also had a large reduction in mileage after my first oil change, but it has not returned. I watched the dealer do the oil change, and used the correct Honda 0-20 oil. They did not do anything else except rotate the tires from front to back. I was averaging about 49 mpg (looking for 50+), and now I am limping along at 46 for the last 2 tanks, worse than even the very first tank. I can't see that my driving has changed at all. I have made some changes including changing the AC levels from 73 to 75, and no AC in the morning commute. Tire pressure remains around 38.

I did read in the manual that the AC will make a dramatic difference in mileage, but have been running the AC all along here in Texas since March, when summer arrives. Guess window tinting comes next.

Bob

Re: 15% reduction in MPG after 1st oil change
 

The key sounds like to make sure you don't change your oil.;)

Re: 15% reduction in MPG after 1st oil change
 

Quick update:

I am now getting 48mpg - much higher than 44-45 I've been averaging (and 46 I was working on) before my oil change - 160miles into 1st full tank after oil change. I am still not sure what happened to the 1/2 tank after oil change but everything is better now.

Re: 15% reduction in MPG after 1st oil change
 

i just got my first oil change done yesterday. i immediately noticed a marked decrease in FE on the iMPG guage as well as on the MPG readout.

i usually average over 50 MPG quite easily...now i'm down to about 44. not quite sure who/what is to blame.

it was a dealer service. i suspect they put in 10w30? regardless, the mediocrity and idiocity of the southern california workforce comes under suspicion. even the service writer initally wrote the car up for a 26.99 oil change rather than the 39.99 for hybrids.

Re: 15% reduction in MPG after 1st oil change
 

update: i've contacted the dealer with little success. apparently they don't make mistakes.

i've driven the car almost 200 miles with little resolution. i have noticed that at lower rpm/speeds the iMPG gauge is severely affected. whereas, at higher rpm's/speeds the fuel economy seems more inline with what the car was getting.
this leads me to believe that perhaps a more viscous oil would have a greater affect at lower speeds and perhaps the oil is not 0w20.

regardless, i just purchased mobil1 0w20, filter and a crush washer. i will redo the oil change myself.

Re: 15% reduction in MPG after 1st oil change
 

Man you guys are scaring me about getting an oil change. I still have another 5000 miles though.

Re: 15% reduction in MPG after 1st oil change
 

I've had my dealer change my oil in my 2006 HCH 3 times now. (I drive about 800 miles to work each week and now have around 21,000 miles on my odometer.) I have experienced a slight decrease in MPG's but it wasn't due to new oil. My dealer readjusts my tire pressure back to "factory specs" (around 35 PSI). I have to remember to pump them back up to 44 PSI (stock Dunlops).

Re: 15% reduction in MPG after 1st oil change
 

OK, PROBLEM SOLVED!

i put my car on ramps, drained the oil, replaced the oil filter, plugged the oil pan, flushed a quart of 0w20, ran the engine for 20 seconds, redrained the flush oil until dripped dry. filled with mobil one 0w20, 3.4 quarts.

i just came back from a 20 mile round trip test drive and averaged 53.3 MPG at 62mph. the iMPG gauge dances like it used to and my mileage seems to agree. the car just feels right.

this was clearly the dealer putting in oil other than the manufacturer's recommended 0w20. i would love to get the drained oil analyzed just to neutralize the arrogance of my service writer at the dealership. what a jerk he was.

it is funny how we get to know the characteristics of our cars, i knew immediately that something was wrong when i was driving it home from the oil change. (9k plus miles of familiarity).

for the benefit of others...symptoms to look for:

the iMPG gauge doesn't move up as dynamically when letting off the gas.
notice that <35 mph driving (engine pulling) reads only 2-3 iMPG bars
yet at higher speeds you are able to max out the iMPG albeit with greater
difficulty.
200 plus miles of driving since oil change with no improvement of FE.

Re: 15% reduction in MPG after 1st oil change
 

I'l bet it's the AC. Think about it. For most of you the last time you changed your oil was in the spring. Now it's summer and your AC is working harder to keep the inside of your car cool. Just my humble opinion. :-)

Kelly