Is it better to fill up to the high mark?

[Marchboom]

The factory engineers put a MAX line on the dipstick for a reason. Why do so many people think they are smarter than the engineers? Race engine builders go to great lengths to make sure the crank does not get into the oil and cause drag.

Just fill the crankcase, leaving out about 1/2 qt. Start the engine, let it run for a few minutes, shut it down, wait about 5 mins or so and then add oil to bring it up to the MAX mark.

Drink beer.

 

[Patman]

Originally Posted By: Marchboom
The factory engineers put a MAX line on the dipstick for a reason. Why do so many people think they are smarter than the engineers?


It's not that we think we are smarter than the engineers, but I would be willing to bet that if you talked to the engineer that developed your engine he would even probably say it was safe to add more oil than the manual says, but that they have to list the amount in the manual at a lower amount just for a measure of safety (since they know that many people will add a bit more)

Besides, you seem to be forgetting where you are. On BITOG we don't always follow things perfectly to the letter just because the manual says so. On here many of us like to experiment with various oil related things and we are fully prepared for any consequences that may occur. That's one of the fun things about this site, is the amount of experimentation that people do.

 

[jsw]

Thanks everyone. This is all very good information.
I did an oil change on my 06 nissan murano this weekend. I added about 4.42 qt and it seems hit the high mark already. The book says add 4.25 qt. During my previous oil change, I added 4.32 qt and it only read just below middle on DS. So by adding 0.1 qt more it move it all the way to high mark. Has anyone seen this on a murano before?

 

[Eddie]

If I have a good running non oil burning engine, why would I waste 1/2 quart of good oil? Like someone said. I seem to fill alway to the full line but, 1/2 way between add & full is still good.

 

[Mitch Alsup]

Originally Posted By: Marchboom
The factory engineers put a MAX line on the dipstick for a reason. Why do so many people think they are smarter than the engineers?


They must be watching Fox News.

Quote:
Race engine builders go to great lengths to make sure the crank does not get into the oil and cause drag.


Real race engines do not leave the oil in a wet sump.

And indeed, for cars with dry sumps, you want the oil level to be spot on the middle of the stick. Excess oil will blow through and get consumed down the intakes as blow by. My Ferrari will consume oil until it gets exactly 1/2 way down on the dip stick, and then not consume another drop in 5000 miles.

 

[Virtuoso]

The oil dip-stick on our Windstar reads like this:

ADD |XXXXXXXXX|
The manaual states you can "over-fill" the crankcase as long as the oil level does not reach past the F in FULL...

Not that they advise to, but it's the only car we've owned with such a statement. 4.5qts and a new filter, and it sits perfectly at the full line.

IMHO over-filling is not a good idea, a little is ok, a lot is not.

 

[Eddie]

Just changed the oil in my Mazda CX7 and the dipstick has a MIN & MAX line. Pretty clear to me what is the correct amount.

 

[hisilver]

call me crazy but i use the recommended amount. If it wasnt a whole number i probably would round up.

 

[Audi Junkie]

Most of my cars take LESS than the amount listed.

I'm more careful about overfilling now, since I hear about issues with intake butterfly valves and "swirl flaps".

 

[Mitch Alsup]

Originally Posted By: Virtuoso
The oil dip-stick on our Windstar reads like this:


And you Windstar has a dry sump?

 

[OilBlazer93]

Quote:
Originally Posted By: Mitch Alsup

The factory engineers put a MAX line on the dipstick for a reason. Why do so many people think they are smarter than the engineers?


They must be watching Fox News.


I think Ford Engineers need to watch Fox News. They would make Care that -work- instead of giving ford its 80s Acronyms.

Besides, a little extra oil (Half quart or less, i agree) will Stimulate the Full Lubrication ability. Anything MORE than that over-full, and i believe you are causing the engine to run Hotter?

I always either one of two things:

1) Round UP a Half quart, because NOBODY has mentioned the Oil Filter so far.. and some people have told me that some Oil Filter placements make them not that effective, and its not really getting a lot of Oil through it;

OR, if im feeling Mechanically inclined for some reason...

a. Add all but One of the Recommended Quarts of Oil. (Car needs 5, add 4. Car needs 6, add 5. Car needs 8? add 7. Like Corvette, Jaguar, and other large-sump cars)
NOTE: IF YOU HAVE A 4-cyl HONDA CRX, JUST ADD 4 QUARTS 5W-30 AND THATS IT.

b. Put Dipstick Back, Put Cap back on )BOTH should be off when draining Oil for maximum Drainage of old Oil, take Cap and Dipstick out.)

c. Start Car, let it run for 30 seconds or so. (This whips it up and Circulates it. Only a little amount of time is needed.)

d. Take Cap off again.. and Add one-half to Full quart of Oil.

This is the Financially Responsible, 100% Constitutional, Real American Technically Detailed "Fox News" approach to get that level very well.

Check again after 10 minutes or so, as this was ALL the Oil dripped out of Head.. didnt really get up there in the First place, but this is the New oil you are checking, so, should be as pretty close to accurate as can be. (Similar to the "M104 Mercedes Benz" approach.)

Oh.. If possible, do on a "Warm" Engine, or one that has sat for 10 to 20 minutes after using it for the day.

 

[XS650]

Originally Posted By: Patman
Originally Posted By: Marchboom
The factory engineers put a MAX line on the dipstick for a reason. Why do so many people think they are smarter than the engineers?


It's not that we think we are smarter than the engineers, but I would be willing to bet that if you talked to the engineer that developed your engine he would even probably say it was safe to add more oil than the manual says,


The factory oil level on a well designed engine is set where it is for engine operation at higher cornering loads, braking loads and side slope operation than the average driver will experience. The fact that backyard experimenters get away with overfilling is more a testament to the robustness of the engine design than the genius of the backyard experimenter.

 

[Virtuoso]

Originally Posted By: Mitch Alsup
And you Windstar has a dry sump?


??? No, it's a wet sump. I guess I don't get what you're saying.

 

[Audi Junkie]

I'd have to say that a slight underfill is probably better than a slight overfill, as long as we are talking about the top of the hash marks as a reference.

 

[jimsgmc]

I always try to top off the oil right up to the full line, But that's just because I'm anal about my truck. Being aquart low won't hurt a thing. It's ok to overfill by 1/2 a quart but not much after that

 

[Patman]

Originally Posted By: jimsgmc
I always try to top off the oil right up to the full line, But that's just because I'm anal about my truck. Being aquart low won't hurt a thing.


If an engine only holds 4 quarts to begin with, a quart low means you're losing 25% of your capacity, so that wouldn't be safe at all IMO. You could end up starving the engine for oil if you drive it hard in the corners.

 

[ARB1977]

I fill to the full mark on a cold engine. Ive noticed more on the Tacoma once the engie is hot the oil is about 1/4" over filled. The Jetta stays pretty much even.

 

[Gene K]

Which is better is engine specific.

For instance the 2.0L DOHC Neon Engines needed to be run at least 0.5 Qt low for sustained high rpm like racing to avoid engine failure. They would get oil up into the crank otherwise and the resulting air would cause oil pump cavitation. On the other hand some year Corvettes are recommended to overfill by a Quart for Open Track.

You could make a case that the ideal level for most engines is half-way in between the full and add marks. After all would not the ideal level be chosen and then the dipstick marked 0.5 Qt to each side of it to keep it as close to ideal as possible?