which is worse? running a quart low or mixing oil?

[fdcg27]

At a qt low, in a typical capacity sump, I'd be adding a quart.
If I had a fill of M1 and I knew I needed top ups, I'd buy a jug at Walmart and keep it on hand for top ups, adding a quart as needed.
There is no point in adding oil when the level is above the "add" mark on the dipstick.
The range between full and low is a safe range for the engine.
That's why the dipstick is marked as it is, and that's why the lower mark says "add" and not "OMG".

 

[TFB1]

The bit about running much hotter doesn't impress me, in the real world I've never seen enough difference in temp to even be noticeable... As long as the pickup is covered and not sucking air, the heat is going to be carried back to cooler or sump in the same manor...

Biggest issue when low would be in cold temp where it would require additional time for the oil to flow back to pan, in this case it's possible to pump the pan dry...

Don't think I'm recommending running your engine a quart or more low(though I will), the point is as others have mentioned a quart or even more isn't the end of the world, the sky won't fall on you...


So what would you guys do with this one??? Yes it's from a vehicle I own that has a 4qt sump(five with filter)...

 

[Durango]

Originally Posted By: jimbrewer
Which is worse, running a quart low, or mixing oil?

A relative is a recent college grad. Working first job with a decent wage, but its kind of temporary. Dad (in another city) arranges to have oil changed on her old car with Mobil 1 at 5k or so when she comes to visit. Its the car she had in high school. The oil was kind of low I think a quart and a half the last time she dropped by for a visit and I happened to be there.

A couple of days later as she drove me to the airport, I told her she should be careful to check her oil every couple of weeks and keep it topped off. She didn't know how, but I told her any guy at her apartment complex would be happy to show her (one of the perks of being a nice looking co-ed type). Given her limited means, I told her not to worry about getting high-dollar Mobil 1, but to get any old name brand oil in her grade, and keep a bottle handy in her apartment. I suggested Mobil 5000.

Did I give her bad advice? Is it worthwhile to top off the oil now that they come in E-Z resealable screw top containers and not cans? Or should we still wait until the oil gets a quart low before adding more?


jimbrewer,

You told her right. Mobil 5000 is fine oil to use and to answer your question keep having her top off the oil don't let the oil level go low! It's much better to teach her good maintenance habits. Good education is hard to come by.

Durango

 

[AmishFury]

Originally Posted By: TFB1


So what would you guys do with this one??? Yes it's from a vehicle I own that has a 4qt sump(five with filter)...

add 2, check level, add more if needed... that is after checking for any noticable leaks

 

[OneEyeJack]

Why would you run your car with the oil level below the "Add" mark on the dipstick? You can buy oil almost anywhere. You can stop at an auto parts store and even ask for help checking oil level. if the level is ever low and you're not driving a "beater" you might be curious about why the oil level is low. Of all the maintenance things you might not be able to do on a modern vehicle, checking the oil is still done the old fashioned way with a dip stick on most vehicles. There must be a reason why all vehicles have not been equipped with an oil level warning light on the dash. Having the oil at the correct level in the crankcase must be considered important by the factories that produce cars.

 

[jrustles]

Originally Posted By: TFB1
The bit about running much hotter doesn't impress me, in the real world I've never seen enough difference in temp to even be noticeable...


Why would a sound warning with full explanation be intended to impress? The only impression I'm trying to make is to deter people from following stupid advice or risking their own equipment. Of course, "in the real world", you're measuring oil temperatures at the bearings and cylinder walls, right?

Quote:

As long as the pickup is covered and not sucking air, the heat is going to be carried back to cooler or sump in the same manor...


I hope you and anyone thinking of allowing that to happen realize that oil flow varies with RPM, that gravity is the only thing returning it and that oil covering the pickup at idle, won't cover the pickup at 4500rpm?

You wanna demonstrate this for yourself.. try filling your dishwasher even 70% low. Turn it on and it'll suck air and water alternately, despite there being plenty of coverage of the pump inlet when you switched it on.

Why not run your cooling system a few quarts low, surely as long as the pump can move it, the total thermal capacity of the system remains, right?

Let's get back to cars. Ever notice that oil gets visibly darker and thicker on the dipstick if consumption is not compensated for? Wonder what's happening to it...

Come on bro