What is with Dealers And Over Filling The Oil ?

[crazyoildude]

I have a friend that leased a new vehicle and he has free oil changes..Why is it that they always overfill it about a quarter of a quart??
Same with my daughters new traverse the dealer always overfills it slightly..

 

[daman]

Really your worried about a 1/4 of a qt? that's nothing wont hurt a thing, I do 1/2 qt over full deliberately every change. Just compensates for any usage through out the OCI.

been doing it for 30 years.

 

[RazorsEdge]

LMAO,nothing to worry about!

As a matter of fact,many drag-strip racers will over-fill the 4.6 motors by at least a quart and never hurt anything!

 

[demarpaint]

Probably because they pull the drain plug, let it drain until the stream stops and put the plug in. Swap the filter, then they grab the dispenser, dump in however many quarts the car calls for and call it done. There's a lot of excess oil in the engine running down that didn't drain because the drain plug was out for a total of about three minutes. Time is money and they're not going to tie up a lift long enough to allow a through draining of the sump. If an oil change takes them 10-15 minutes including driving it into and out of the shop it's a lot. If you're over by a 1/4 qt. consider yourself lucky, they allowed an extended drain time.

 

[NHGUY]

Probably covering the engine in case it burns some.You know people don't check the oil regularly....Or else their bulk oil dispensing system isn't calibrated correctly.

 

[fdcg27]

More than likely they've learned the hard way that a little overfill is better than a little underfill.
Most drivers aren't Bitogers and most Bitogers will pass up on even free dealer oil changes.
Most drivers will never check the oil level between drains so a little overfill is a little cushion.
I've routinely put five qts in a 4.5 qt sumps and never had any problem as a result, and I'm speaking of cars we had well past 150K from new.
I wouldn't sweat a minor overfill and the dipstick isn't a precision instrument anyway.

 

[MolaKule]

Incorrect Oil Psychology (IOP) 101: Just a little more is better than Full.

 

[eljefino]

The bulk dispensers have a readout down to the 0.1 quart but the ones I've used don't stop at a prescribed level.

I put (by my guess/ experience) 1/2 a quart too little in, started it up to fill the filter, stopped, checked the stick, and topped off. Others may not be so conscientious.

It's like having slightly too much air in your tires. It's easier to leak out than in.

 

[OneEyeJack]

Better the under filling or forgetting to fill at all. Besides, they are probably using oil from the low bidder.

 

[turtlevette]

I added more oil to my mustang where it was just a bit above the top hole on the stick, about 1/8" We'd smell a sweet burning smell when at a stop. I had always s argued a quart extra was no problem but this proved me wrong. Or proved I shouldn't have bought a pos ford.

I drained and refilled and the smell is gone.

 

[funflyer]

Have you guys ever heard of windage? Yes overfilling is worse than underfilling. Now, a 1/4 quart is probably not going to hurt anything on most vehicles but on some it will rob HP and decrease MPGs.

 

[RazorsEdge]

Originally Posted By: funflyer
Have you guys ever heard of windage? Yes overfilling is worse than underfilling. Now, a 1/4 quart is probably not going to hurt anything on most vehicles but on some it will rob HP and decrease MPGs.


Yup,heard of it and again,I know alot of people that over-fill at least 1/2 to full quart,never have issues.

If you think dipsticks for all vehicles are 100% accurate,your fooling yourself.

 

[Leo99]

Originally Posted By: MolaKule
Incorrect Oil Psychology (IOP) 101: Just a little more is better than Full.

Just like sizing oil filters. A little bigger is better than the regular one.

Just like viscosity. A little thicker is better than the recommended viscosity.

Just like jack and jack stand ratings. A little heavier is better than the what's needed.

 

[funflyer]

Originally Posted By: RazorsEdge
Originally Posted By: funflyer
Have you guys ever heard of windage? Yes overfilling is worse than underfilling. Now, a 1/4 quart is probably not going to hurt anything on most vehicles but on some it will rob HP and decrease MPGs.


Yup,heard of it and again,I know alot of people that over-fill at least 1/2 to full quart,never have issues.

If you think dipsticks for all vehicles are 100% accurate,your fooling yourself.


Part of the engineering that goes into engines is directing oil drain back to the sump around and away from the crankshaft to avoid excess drag. I doubt they just willy-nilly mark a dipstick also, they are accurate.

 

[Leo99]

Originally Posted By: funflyer
Originally Posted By: RazorsEdge
Originally Posted By: funflyer
Have you guys ever heard of windage? Yes overfilling is worse than underfilling. Now, a 1/4 quart is probably not going to hurt anything on most vehicles but on some it will rob HP and decrease MPGs.


Yup,heard of it and again,I know alot of people that over-fill at least 1/2 to full quart,never have issues.

If you think dipsticks for all vehicles are 100% accurate,your fooling yourself.


Part of the engineering that goes into engines is directing oil drain back to the sump around and away from the crankshaft to avoid excess drag. I doubt they just willy-nilly mark a dipstick also, they are accurate.


Why don't the engineers design engines to hold 5 qts or 5 L or some round number? Why 4.8 qts? They have to assume people will just dump in 5 qts anyways.

 

[HTSS_TR]

Originally Posted By: MolaKule
Incorrect Oil Psychology (IOP) 101: Just a little more is better than Full.

I filled my E430 with 8.5 quarts as in owner manual after carefully extracted approximately 8.0-8.2 quarts with Mityvac. The car's computer complaining about overfilled every time I started the engine, I checked and the oil level was about 1-2 mm above full line, I had to extract 1/2 quart to quiet the dang oil monitor. After that event I filled 8 quarts only, no problems so far after 12-13 years.

 

[RazorsEdge]

Originally Posted By: funflyer


Part of the engineering that goes into engines is directing oil drain back to the sump around and away from the crankshaft to avoid excess drag. I doubt they just willy-nilly mark a dipstick also, they are accurate.


Experience says otherwise ...

 

[RoadRaceJosh]

My Frontier is supposed to get 4 and 7/8 quarts. 1/8 quart is a paltry 4 ounces so the whole 5 qt jug goes in at service.

Back in 1991 when I changed oil for a "living" I put in what was called for and checked it after running to check for leaks. A small over-fill wasn't enough to worry about trying to drain.

 

[CT8]

A whole quarter of a Qt !!!!

 

[dareo]

Some shops consider dipsticks to be too inaccurate and simply fill to the book capacity. I think they are just not letting the oil drain down before taking the dip stick measurement. Big difference in the engine just shutting down and it sitting for 15 minutes in the dip stick level. I shoot for 3/4 up the dipstick and then top it to full after it has sat all night. But you know, #bitogperfectoilchange