The myth of putting too much oil

orenf · 03-27-2008, 12:05 AM

What with winter almost behind us, I've finally managed to get back on the +50MPG track for the last couple of tanks.
Then it was time to take my Prius to its first ever oil change, at just slightly over 5k miles. Just had to get rid of that annoying "SERVICE" light.

I remember reading about the "DON'T LET THEM PUT TOO MUCH OIL IN" issue, but at the time (last week) it didn't cross my mind. I went to the dealer, gave them the car, had it done in less than an hour, and was on my way to work.
Over the next 5 days, my MPG was hanging by a thread above 45. The car felt a bit "heavy" when accelerating, but more obvious was the impact on the hybrid system: it was difficult to glide, and when in EV or regen mode, it rarely showed the friendly 99.9 MPG reading. Instead, I was getting anywhere between 20-60MPG, when EV or regen (with or without brakes), long after the engine "warm up" period.

Last night I could stand it no longer. I went and checked the oil level. Lo and behold - it was about an inch or so over the top. I then went back and checked the receipt from the dealer. Sure thing, they put in 5L (=5.3 quarts) of oil.

This morning I went back to the dealer, expecting all sorts of objections, armed with the TSB discussing this issue. By the time I arrived, I was showing 44.6MPG over 120 miles.
Being Canadians, they didn't even put up a fight... they claimed "it makes no difference", but went ahead and drained it anyhow.

The improvement was immediate - as soon as I pulled out of the dealership, I was able to glide (most of my way) to work. The car feels "lighter", and all is well.

I'm back on track, and with luck I should be able to hit 48MPG for the tank.

At least for me, the "too much oil" myth is no myth. Lesson learned.

--- Oren

hobbit · 03-27-2008, 12:19 AM

Wow. That's a lot of excess oil. The tech who didn't read the
spec should be required to smear it all over his body.
.
_H*

Godiva · 03-27-2008, 01:11 AM

I hope they refunded you for the extra liter you were charged for and didn't need.

orenf · 03-27-2008, 02:05 AM

Quote:

Originally Posted by hobbit

Wow. That's a lot of excess oil. The tech who didn't read the
spec should be required to smear it all over his body.
.
_H*

As they were draining the excess oil, they took my car up-and-down 3 times. up - drain - down - check - up - drain - down -check etc.

I think they were quite surprised as just how much they had to drain. I remember reading here that the dip stick isn't linear - it takes a lot more oil to move the level when it is high than when it is low.

orenf · 03-27-2008, 02:08 AM

Quote:

Originally Posted by Godiva

I hope they refunded you for the extra liter you were charged for and didn't need.

Hmm... Good point. I believe I've been living in Canada for too long. It's rubbing off on me. I was just pleased I didn't have to yell at anyone to get it done...
Sheesh. It only took 3 years of living in BC to completely override the 5 years I had spend in NYC.

edthefox5 · 03-27-2008, 04:23 AM

Quote: Being Canadians, they didn't even put up a fight...

Thats funny.Thank you.

bbald123 · 03-27-2008, 05:53 AM

Quote:

Originally Posted by orenf

<snip>...At least for me, the "too much oil" myth is no myth. Lesson learned.

--- Oren

Myth? Over filling ANY engine with oil is a big no-no. Frothing can lead to all kinds of problems. Anyone that says over filling isn't an issue, isn't informed.

patsparks · 03-27-2008, 06:12 AM

I bet it's nicer living with Canadians who don't put up a fight, so don't fight the Canadian infusion. Canadians sound like nice people.

xsmatt81 · 03-27-2008, 08:18 AM

the same thing happned to me the first month. I had about 1600 miles. And thought I should toss the dino out for some mobil-1 syn. Went and picked up the usual 5 quart. I was pressed for time so i didn't do it myself, and just took it to a jiffy lube. I specfically told the tech 4 quarts. Later that night pulled the dip stick and it was probably 2 inchs or more above full! i freaked out and didnt drive it for a day or so. Anyway i did it myself and put the proper amount in. The small miles i drove probably had no affect, but still, these guys are paid to work on cars, fix things...sigh

On my older car i would change the oil out all the time, but with prius i've just been doing the dealer route. A good bit of advice is go buy your own quarts. you can do the case, or 5-quart jugs for 20 bucks at walmart, and it's synthetic. pour out about a quart into either an empty quart bottle, or a pan, whatever- bring that to them and no need to worry! they can't over fill then.

richard schumacher · 03-27-2008, 10:39 AM

Always, always, always check the oil level yourself before driving away from an oil change. This can find and prevent some gruesome errors and expensive repairs.

BTW, 3 US quarts of oil is plenty at an oil change. This leaves the level halfway between the ADD and FULL marks on the dipstick. If you provide the oil it also saves money, prevents overfills, and does not result in a partial bottle of leftover oil.

03-27-2008, 12:05 AM	#1
orenf Senior Member Join Date: Jun 2007 Location: Vancouver, BC Posts: 110 My Car: 2007 Prius Model: Package: #2 Thanks: 3 Thanked 1 Time in 1 Post Friends: 0	The myth of putting too much oil What with winter almost behind us, I've finally managed to get back on the +50MPG track for the last couple of tanks. Then it was time to take my Prius to its first ever oil change, at just slightly over 5k miles. Just had to get rid of that annoying "SERVICE" light. I remember reading about the "DON'T LET THEM PUT TOO MUCH OIL IN" issue, but at the time (last week) it didn't cross my mind. I went to the dealer, gave them the car, had it done in less than an hour, and was on my way to work. Over the next 5 days, my MPG was hanging by a thread above 45. The car felt a bit "heavy" when accelerating, but more obvious was the impact on the hybrid system: it was difficult to glide, and when in EV or regen mode, it rarely showed the friendly 99.9 MPG reading. Instead, I was getting anywhere between 20-60MPG, when EV or regen (with or without brakes), long after the engine "warm up" period. Last night I could stand it no longer. I went and checked the oil level. Lo and behold - it was about an inch or so over the top. I then went back and checked the receipt from the dealer. Sure thing, they put in 5L (=5.3 quarts) of oil. This morning I went back to the dealer, expecting all sorts of objections, armed with the TSB discussing this issue. By the time I arrived, I was showing 44.6MPG over 120 miles. Being Canadians, they didn't even put up a fight... they claimed "it makes no difference", but went ahead and drained it anyhow. The improvement was immediate - as soon as I pulled out of the dealership, I was able to glide (most of my way) to work. The car feels "lighter", and all is well. I'm back on track, and with luck I should be able to hit 48MPG for the tank. At least for me, the "too much oil" myth is no myth. Lesson learned. --- Oren __________________ Join me on LinkedIn - View My Profile Visit my blog - all about importing a Prius to Canada

03-27-2008, 12:19 AM	#2
hobbit Senior Member Join Date: Mar 2005 Location: Bahstahn Posts: 3,630 My Car: Model: Package: Thanks: 0 Thanked 216 Times in 118 Posts Friends: 0	Re: The myth of putting too much oil Wow. That's a lot of excess oil. The tech who didn't read the spec should be required to smear it all over his body. . _H*

03-27-2008, 01:11 AM	#3
Godiva AmeriKan Citizen Join Date: Apr 2005 Location: San Diego, CA Posts: 10,342 My Car: 2005 Prius Model: Package: #1 Thanks: 0 Thanked 1 Time in 1 Post Friends: 7	Re: The myth of putting too much oil I hope they refunded you for the extra liter you were charged for and didn't need.

03-27-2008, 04:23 AM	#6
edthefox5 Senior Member Join Date: Jul 2007 Location: Clearwater, Florida Posts: 598 My Car: 2007 Prius Model: Package: #2 Thanks: 1 Thanked 14 Times in 12 Posts Friends: 0	Re: The myth of putting too much oil Quote: Being Canadians, they didn't even put up a fight... Thats funny.Thank you.

03-27-2008, 06:12 AM	#8
patsparks An Aussie perspective Join Date: Jul 2007 Location: Adelaide South Australia Posts: 9,265 My Car: 2004 Prius Model: N/A Package: Base Thanks: 128 Thanked 185 Times in 143 Posts Friends: 33	Re: The myth of putting too much oil I bet it's nicer living with Canadians who don't put up a fight, so don't fight the Canadian infusion. Canadians sound like nice people.

03-27-2008, 08:18 AM	#9
xsmatt81 non-AARP Member Join Date: Mar 2008 Location: Vegas Posts: 511 My Car: 2007 Prius Model: Package: #3 Thanks: 1 Thanked 5 Times in 5 Posts Friends: 0	Re: The myth of putting too much oil the same thing happned to me the first month. I had about 1600 miles. And thought I should toss the dino out for some mobil-1 syn. Went and picked up the usual 5 quart. I was pressed for time so i didn't do it myself, and just took it to a jiffy lube. I specfically told the tech 4 quarts. Later that night pulled the dip stick and it was probably 2 inchs or more above full! i freaked out and didnt drive it for a day or so. Anyway i did it myself and put the proper amount in. The small miles i drove probably had no affect, but still, these guys are paid to work on cars, fix things...sigh On my older car i would change the oil out all the time, but with prius i've just been doing the dealer route. A good bit of advice is go buy your own quarts. you can do the case, or 5-quart jugs for 20 bucks at walmart, and it's synthetic. pour out about a quart into either an empty quart bottle, or a pan, whatever- bring that to them and no need to worry! they can't over fill then. Last edited by xsmatt81; 03-27-2008 at 08:22 AM.

03-27-2008, 10:39 AM	#10
richard schumacher Destination: Eschaton Join Date: Mar 2004 Location: United States Posts: 5,515 My Car: 2004 Prius Model: N/A Package: #6 Thanks: 100 Thanked 93 Times in 66 Posts Friends: 0	Re: The myth of putting too much oil Always, always, always check the oil level yourself before driving away from an oil change. This can find and prevent some gruesome errors and expensive repairs. BTW, 3 US quarts of oil is plenty at an oil change. This leaves the level halfway between the ADD and FULL marks on the dipstick. If you provide the oil it also saves money, prevents overfills, and does not result in a partial bottle of leftover oil.