Oil overfill

I believe that all the overfil does is hurt MPG numbers marginally.

 

Gurmail,
The Toyota manual says that overfilling the engine can cause stress to the engine and the Hybrid System. It's also bad for your gas mileage. This of course though, is if way too much is put in your vehicle. 1/3 inch doesn't sound terrible, but if I were you, (to ease my mind and for the engine) I would go to the nearest Toyota place and have them drain a little bit at your convenience. It won't take long and they will to it for free. Congratulations on your new Prius!

 

Problem is we don't know how much margin for error there is, or where it is. Maybe Japanese automotive practice assumes that halfway between "ADD" and "FULL" is the nominal point, and that all of the margin for error is around that nominal point. In that case the "FULL" mark itself would be the top end of the margin for error.

Note, from the owner's manual, that putting in exactly three quarts of oil (a nice, round, ideally convenient amount) fills the system including filter almost exactly to the halfway point, leaving plenty of margin for error (incomplete drainage of the old oil, not getting every drop from each bottle, the grease monkey getting careless while reading the flow meter on his oil hose, and so on). I keep mine around the halfway point. None of that fooling around with partial quarts of oil and inspecting the dipstick with a micrometer, and no worries :_>

 

I do exactly the same thing. Until my Prius shows signs of burning oil, it seems to be the best option. In addition, you save 25% on oil costs.

 

My locoal Toyota dealer said it was VERY important NOT to ovefill the oil because with all the different pumps it might back up the oil into the intake manifold and cause a no start condition. I was happy that my locoal dealer seemed on the ball and was very knowlegable about the Prius.

 

In my case Belle was over filled by a similar amount I would call it one to two finger breaths. Unfortunately I did not discover it until Saturday and the service department was closed. I was directed to a (very) young but very knowledgable manager a of all places Jiffy Lube. I would guess that he was just out of high school. He knew a lot about my car including displacement, the fact it ran on the Miller cycle (by name), offered to check my tires and increase the pressure over factory and drained the oil out for free. There is hope for the future of America. Kids that worked on jalopies 30 years ago know about Hybrid technology. We had a nice chat while he supervised his crew.

 

My dealer agrees that it is crucial not to overfill at all. The oil will get into the intake manifold as mentioned before.

They use 3.5 Quarts instead of the 3.9 the manual calls for.

 

Hey isn't it really nice when you meet a kid who is REALLY on the ball! I hope you told the higher ups at Jiffy Lube what a good employee they have there

 

Regarding oil changes, two suggestions that I have gathered from this BBS have been extremely helpful.

1. Prefilling the oil filter with oil...a really good common sense idea that I never considered in over 30 years of car maintenance. It appears that by doing this oil pressure is immediate as the filter is filed and the "engine oil level" will not be decreased by the initial fill into the filter and


2. The fumoto valve - with this valve it is extremely easy to "adjust" or bleed off any overfill.