Average car Overfilled 1 qt. anyone ever see this cause a problem?
- Thread starter WobblyElvis
- Start date
Having less than 5 quarts really upset me when I owned a 3.8 liter GM engine.
My neighbor who is a chemist maintains that if it says 5 quarts, you can go 1 either way and be fine. If it says 5.0 quarts, then you can go 1/2 either way, and so on
The greater detail they specify, the less wiggle room there is
Sounds logical I guess, never really figured if it applies to cars
The greater detail they specify, the less wiggle room there is
Sounds logical I guess, never really figured if it applies to cars
At least a .5 is sorta doable if so inclined. I really don't understand manufactures that list oddball capacities like 4.65, 3.91, 6.34, 5.07, etc...
Thinking out loud here, do the engineers come up with these numbers or someone else in the command chain? You think it would benefit the dealers and the DIY consumers to just keep it a whole number.
I’d agree with his idea. However I think he’s assuming the engineers wrote the owner’s manual. Which may or may NOT be the case.
Sorry for second post, but great point! They also have to contend with the fact that the general public by and large hardly ever even check their oil level, let alone change it themselves. I can’t tell you the amount of people I work with who are purported to be “smart” who don’t know what engine is in their high end car, or what wt oil it takes!
Good question. Perhaps some software was used during engine development to find the optimal capacity while following certain design constraints. These aren’t numbers that a person would normally pick.
Of course then there is situations like my Generac that says it takes 4 quarts. 4 quarts doesn't even get you on the dipstick! It really takes 5 quarts to get to the full
Personally, I'd think 10% over/under is acceptable but I like your thought process.
I routinely pour the full five quart jug in my engines that specify 4.5. No issues so far..
I'm probably old school (maybe dumb school) but I think an oil level anywhere between the add and full marks is just fine.
When changing oil I aim low and and add oil until I get close to the full mark. Between changes I never add oil unless the level gets below the add mark - which it never does - which means I never add oil. I don't believe in topping up. I don't think my approach has ever hurt anything.
But then I only keep my cars for +/- 20 years.
When changing oil I aim low and and add oil until I get close to the full mark. Between changes I never add oil unless the level gets below the add mark - which it never does - which means I never add oil. I don't believe in topping up. I don't think my approach has ever hurt anything.
But then I only keep my cars for +/- 20 years.
Anecdotally, I believe + or - 1.0 qt is within the tolerance of most engines and won't cause a problem. Years ago I posted about my 1995 Chevy PU 5.7L being double filled at a WalMart. They put in 12 instead of 6. I drove it for a day before it was corrected. The engine suffered no damage. Other times, I have inadvertently overfilled by 1, and also inadvertently let levels fall just below 1 qt. I never experienced any damage. Past that, all bets are off. Also consider driving in the hills or mountains, or banking hard. That effectively changes the level in the pan significantly. Engines are tougher than most people think.
How you drive the car is an unrelated, separate issue.
Carlostrece
$100 Site Donor 2025
My dad and mom sometimes overfilled their cars 1 quart. No problems were ever observed. They drove moderately. If someone drives hard then it might matter.
Jiffy Lube once overfilled my mid 80s Oldmobile I used to own with 4 extra quarts. That was an obvious problem, even driving moderately. Blue smoke from tailpipe, oil leaks, a mess. However, after draining out the extra oil it was fine, other than oily messes left behind. Maybe also a slightly weeping gasket &/or seal that was never the same again.
After that, no more Jiffy Lube. I went back to DIY.
Mine day 4.8 qts. I add 5 qts and no problems yet. I might trade in my Camry but it's running great. Be hard to let it go.
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It's most likely that the spec wasn't originally based on quarts but instead is based on liters and then just converted over for the American version of the owner's manual.
Focus needs 4.3l but it gets 5 every time, Outback is 4.8l so it gets 5 every time too. The Focus does seem to use some oil now, maybe a quart every 3-4k miles, so for an 8k miles OCI I usually add a quart of something, often 15W40 these days as the pail is always open and handy and I don't buy anything other than 5l jugs for the cars.
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