My Gas Pips Have Been Falling Fast

Thanks for the update macmaster05. It's good to see that they took it seriously. I was kinda expecting that they might have been a bit dismissive or defensive about it.

 

I've read these types of threads with interest and after the first oil change on my 2010, sure enough, it was overfilled, by 1/8 - 1/4. I didn't find it until I was home and checked it on the weekend. I did not find the car ran any differently and there was no impact on the mileage. I wonder if the 2010 has more latitude than the Gen II as far as overfilling. Has anyone seen a mileage drop with overfilling on a 2010?

 

People get really worked up over the engine oil being overfilled and wondering if their car is going to explode or be ruined forever and its just unfounded. A real massive overfilling is one thing, but 1/4 a quart isn't going to do anything...

If the shop puts 4 quarts in instead of 3.9...your Prius will survive.

 

and they all lived happily ever after!

 

Not neccessarily. It's just good customer relations that if they see that you're concerned about it then they should also be concerned about it.

Personally my experience has been the same as that of DetPrius and SW03ES. People who have drained the excess have verified that it's only about an extra 200 mL. I've had mine overfilled 1/8" to 1/4" several times and while I don't think it's a good thing just the same I've never noticed any effect on either performance or fuel consumption.

 

My 06 was overfilled by about 1/3 inch above full mark for a few weeks after a dealer service, and I didn't notice any ill effects as far as mileage. But I finally got sick of looking at it and drained some out via the dipstick tube, and yes draining about 250ml did it. However I have noticed it on the classic GEN1 03, (which they also overfilled that regularly) it went down over some time to maybe 38mpg (regular 48-51) then soon after that it died (triangle of death) and PS warnings on the MFD, check eng light etc. etc. it needed the throttle body and MAF cleaned. This only after having to tow it to the dealer (aprox. $90) on a flatbed and then the dealer charging another $290 to fix it. Not to mention all the strain on the oem hv battery trying to start up and move it etc.
Did you know the dealer charges $100 just to read a code? That's insane! Anyway all that was before I started working the cars on my own and now have the capability to read and clear codes. The problem with overfilling is the oil vapors will get up into the intake manifold and throttle body etc. especially when starting cold - it sucks some excess oil up through the vacuum lines, also the pvc valve can get saturated w/oil. Also when the ice warms up and as you reach higher rpms, the accumulated effect over a relatively short time is your mileage will suffer until something gives in the system, mine was the MAF. Now if they fill it 1qt. over- that will damage seals in the ice very quickly. The bottom line - always check your dipstick after an oil change regardless of who did it. Then you will never go wrong.

 

Exactly, you found a shop that actually seemed to care about you being satisfied...a rare thing anymore. They drained the oil because it was important to you which is what they should have done.

However had you never addressed it you would have been fine. If engines were that picky about the exact correct amount of engine oil we'd have engines blown up all over the place because of the hacks that change oil in shops all over the country. I would say 70% of all the cars on the road probably have slightly too much or too little engine oil...and they're fine.