This is quoted from the monthly Valvoline news letter I get. Dan Dotson, Valvoline's Product Development and Technical Services Manager, was interviewed about the properties of racing oil vs. oil that you use on the street:

Ask Dotson about racing oils and he'll tell you that the oil that is poured through race cars is not always the same oil you buy to put in your own car or truck, although they carry many of the same properties. Race engines have special needs and even have needs that can vary according to the race track.

"When you have qualifying a team might want to use an ultra-low viscosity motor oil," Dotson says. "Lighter, more efficient oils produce more horsepower. In some series for qualifying runs, teams simply run a few quarts of oil through the engine, drain it out immediately and then go qualify," Dotson says. "The idea being that a film of oil can get to the engine that allows it to last for two or three laps, but the car does not then carry the extra weight of five quarts of oil."

Conversely, according to Dotson, race teams can use a thicker oil on shorter tracks where air flow is reduced and the engines run hotter. Longer superspeedways allow for a lighter oil, while road courses and intermediate tracks have their own demands.

They actually drain out all the oil and go out and run laps ?

 

Sure sounds like it. I dont see how anything would hold together under WOT.

 

Remember, we're talking about engines that get torn down and bearings replaced after each such run. Bearings probably have a enough babbit to compensate for any WOT rubbing that may occur with oil film breakdown.

I guess it's possible... but not on my engine!

 

its like that slick 50 commercial from a couple years back, and dont forget this is only going on for a couple laps and then being completely torn down and rebuilt(must be nice to have that money)

 

These guys must have their stuff tuned to the absolute max if the weight of 5 quarts of oil means the difference between qualifying or not. Still hard for me to believe.

 

Probably not just the weight, but the drag on the crank, oil pump, etc.

 

I really don't think that Busch or Nascar teams are going
to qualify without any oil in the pans or tanks

For one thing; when qualifyings done they have to race
that motor for 400-500-600 miles including race practice.
If they replace the engine, upon proof thiers something
wrong with it, they have to go to the back of the pack.

No oil-doubt it.
Lite oil- believe it

Later

 

I don't beleave this is a valid statement "today". I also can only think of a couple of series where this could have been beneficial.
For instance, a few years ago F1 had special qualifying cars that were only used for that purpose. Everything about these cars were different from the "normal" race cars. And only in a series like F1 would 20lb.? of oil make any difference.
However this stopped several years ago. Today teams have to practice and qualify with thier race car, and race TWO events per engine, or be penalized.