Optimal engine oil level with high rev driving

[OilUzer]

What is the best engine oil level for continuous high rpm driving or for example when you take your car for a spin on a race track?

Do you keep the engine oil level below the F mark or keep the oil level a little (quart? or so) lower?

I was watching some car show on TV about it (lower oil level) producing a few more HP snd less splashing and foaming, etc.

The hp gain didn't seem significant to me. I always wonder when people say you gain or or lose 5 or 7 hp at 5500 rpm doing this or that and the engine has 4 to 500 hp to begin with ... i.e. The loss or gain is insignificant to me but I neither race nor am I ever near those high RPMs for long.

Anyway, curious about oil splashing or hp gain or any other advantages if you keep the oil level below F.

 

[ctechbob]

Windage is real, and can sap HP away from the engine, foam the oil, and a few other things. Most cars these days are designed to mitigate that as much as possible since it hurts fuel economy as well.

As for how much oil to run in the car? That is going to depend on the car. There are cars that will oil starve super easy and some that won't. When I was tracking my Miata I would keep it just at the F mark and never had any oiling issues, but that car wasn't known for it. Stock 4th gen F bodies with their LS motors couldn't tolerate sticky R-Comp tires on track unless they were run with an extra quart or two without starvation issues as I recall. Memory is fuzzy on that one, but the point is there's no blanket prescription that covers every car running on track.

Yes, you don't want the crankshaft splashing through liquid oil, but you don't want dry bearings either. Once you get into serious race engines and the like you start doing things like knife-edging crankshafts to make them cut through the air and oil mist easier, etc. If you're running a bone stock or lightly modded car on track, keep the oil at F or slightly above and have fun.

 

[Jetronic]

I'd fit a decent windage tray first. Then keep the oil to the full mark. The wider the sump, the shallower the level will be and more likely to suck air during high G stuff.

 

[Srt20]

In my oval track race cars with small block chevys, the oil pans were built to handle this issue.
Though I did run a GM racing crate engine for a bit, and I ran that engine 1 qt low on oil. Never sucked air.

 

[DriveHard]

I run my Fiat right at the "F" mark for autocross days...never seemed to have a problem with it other than heat on a hot day.

 

[Snagglefoot]

If you are super interested in this, drop the oil pan and take some measurements. With the dipstick in place measure where the end of the dipstick is relative to the sump, the windage tray, ( if it has one), and the bottom of the crank counterweights ( if it doesn’t have a windage tray). Remember that the dipstick is slanted so one inch of length on the dipstick is not one inch of depth.

 

[supton]

What engine? I have to think that any modern engine won't care, as long as it's around full and used within normal spec--if you chip it and raise the rev limiter, then all bets are off. Old school motors were pushed outside their design envelop and IMO that was where most of the problems with this came from. OEM's today aren't going to leave (much) off the table when it comes to performance, not when a windage tray is easy to add. Plus I wouldn't be surprised if any oil aeration would cause emissions problems, and thus be a big incentive to control.

On track day I would keep it close to F, for both controlling oil temps and in case of oil consumption. Otherwise... I wouldn't think about it, not until a problem shows up.

 

[IndyIan]

For hypermiling some people will run the engine a quart low or at the low mark, less oil in the system to warm up and presumably the oil runs a bit hotter decreasing viscosity and resistance.
For some cars on track days, I've read people run the oil over the full mark to help avoid sucking air, and I guess foamy oil is better than no oil going through the motor. Also during a hot lap the car always has some acceleration forces acting on it so the oil is never sitting level in the pan.

 

[DGXR]

Racing is severe usage. I always default to FULL oil level for any severe usage, including towing/hauling, long uphill runs in hot weather, etc.
Some brands/models actually recommend switching out the oil for a heavier grade when going to the racetrack (e.g. Corvette).
For normal usage, I just keep the oil level anywhere between the marks on the dipstick, never once had an oil-related issue.