Poor Mileage Since Oil Change

[richard schumacher]

Originally Posted by yardman 49

So this brings up another question for me: why trust the dipstick?

I just had the first oil change done on my 2009. I told the Toyota dealer's shop that I didn't want it overfilled. In response the service writer told me that they had to put in the recommended amount.

When they finished, he gave me me a printout from Toyota that clearly states that an oil and filter change should take 3.9 quarts of oil. When I checked it when I got home, the dipsticked showed about 1/4 to 3/8 inch over the full mark.

So should I leave it as is, or drain some out. And if I should take some out, can I use one of those oil suction pumps to pull it out through the dipstick tube?

What Shawn wrote: It's an error that Toyota never corrected. The dipstick does not agree with the owner's manual or the shop manual. I finally decided to trust the dipstick, because the dipstick design comes direct from the design engineers, whereas the information in the manuals went through two translations: one from the design engineers to the technical writers, and again from the Japanese manual to the English manual.

You can ask that dealer to drain out some, but they did warn you in advance that they would add the recommended amount. If they won't do it, do it yourself or have another dealer do it. For future oil changes use a dealer who will add oil per the dipstick. You can increase the odds of success by buying *three* quarts of oil and giving them to the dealer to use. Warn them not to add any of their own oil and tell them that you will check the dipstick before leaving.

[yardman 49]

Thanks, Shawn, Richard, and anyone who answers the following questions.

Any advice on removing the oil? On cars I've owned in the past, I've quickly removed the drain plug and put it back in again.

Is there any problem with doing this with the Prius? I hear that the seal is an o-ring. So I have some questions for those who have changed the oil themselves:

- Any danger of the o-ring not staying on the plug when I remove it?
- Is the o-ring good for many uses, or does it get replaced every time the plug is removed?
- Is the plug easy to get started in the drain hole, or is it "finicky" and easy to cross thread? As there will be oil pouring out when I'm trying to install it, this could cause an issue.
- Any particular torque setting specified, or just the usual guestimate?
- What's the best way to access the plug: front, side, jack or no jack? I also have ramps.

Thanks for any advice here. I'm leaving tomorrow on a long trip, and want to drain some before I leave.

Thank you!

[Shawn Clark]

The crush gasket in the plug should reseat. Some folks reuse them repeatedly. I have used one for 2-3 changes on other vehicles. If you go that route, then torque the plug back down to recommended setting (28 ft-lb -- for some reason Toyota deigned not to put this in the owner's manual, but it can be found in their procedure and in the Bentley manual.) The concern I would have is that it might leak a little if done as you describe, but that's just me being cautious.

I think it would be difficult to remove the plug and get it back in again with the oil pushing its way out--I've tried to do something like that before for other reasons and it was a mess when I fumbled the plug. (It's especially hard to do if the oil is hot...)

[Politburo]

Would it be easier to remove the filter and take some oil out that way? Just a thought. I've never done such a thing.

[2009Prius]

Originally Posted by yardman 49

...

Any advice on removing the oil?

...

I am new on DYI car care and find using a pump to suck up oil through the dipstick hole very easy to do. Good luck!

[yardman 49]

Originally Posted by 2009Prius

I am new on DYI car care and find using a pump to suck up oil through the dipstick hole very easy to do. Good luck!

Thanks, everyone. That's exactly what I ended up doing. I have a a Craftsman "oil siphon" jug that I use for sucking the oil out of my yard equipment engines instead of trying to drain it from underneath. The hose was the perfect size to snake down the dipstick tube. Very easy to pull out the right amount.

I have another free oil change left at the dealer. So the next time that I get it changed, I'll probably just let them do their thing, then come home and pull a little out. They'll be happy ("we have to put in the Toyota recommended amount..."), and the Prius will be happy.

After that I'll probably just start changing it myself.

Best wishes,

[cfvettes]

The more I read and think about it .... it must be the oil. We had the oil changed at EZ Lube and god only knows what kinda oil they used. We asked for 5w30 but who really knows. But it sounds as though I should use 0w30 to improve mileage too. I think next time I will do the oil change myself and use the 0w30. Would synthetic be even better?

I checked the tire pressure too. I believe they did actually let air OUT of my tires cuz they were at about 32. I couldnt believe.

I bet between both the oil and tire pressure issues, our mileage will return. I will post when I find out.

Thanks all for the responses too by the way.

Charles

[cfvettes]

Originally Posted by Politburo

Would it be easier to remove the filter and take some oil out that way? Just a thought. I've never done such a thing.

I suppose to drain some out, you could always pull the plug and just let it all drain out into a nice clean container. Then clean the plug and pan, re install the plug, pour out a half quart before pouring it right back in.

Charles

[ETP]

Originally Posted by yardman 49

So this brings up another question for me: why trust the dipstick?

I just had the first oil change done on my 2009. I told the Toyota dealer's shop that I didn't want it overfilled. In response the service writer told me that they had to put in the recommended amount.

When they finished, he gave me me a printout from Toyota that clearly states that an oil and filter change should take 3.9 quarts of oil. When I checked it when I got home, the dipsticked showed about 1/4 to 3/8 inch over the full mark.

So should I leave it as is, or drain some out. And if I should take some out, can I use one of those oil suction pumps to pull it out through the dipstick tube?

Thanks

I have yet to buy a lawnmower that will take all the oil the tag on the block says it will. So what is correct? I think the people that throw this stuff together are not as accurate as we think. And unless we take an engine apart and measure the volumes we would never know. We just have to guess and hope that we are right.
If it runs, gets good mileage, and does not make noise then leave it alone.

[cfvettes]

I called the place that did the oil change and they said because our car was an older Gen II and because we had 80K miles, no doubt our hybrid batteries were wearing down, getting weaker and unable to deliver power like they used to. He said in this case more power comes from the engine with less contribution from the hybrid motor. Leading to a decrease in mileage.

Could this be true? And how do you know when its time to change the hybrid battery?