It is obvious that oil may give you more horsepower. How? By reducing the amount of strength the crankshaft has to make to turn itself. You can say; no! that gives the engine better torque by reducing friction. Folks, it's this simple; take a pen with one hand and try to rotate it the other way with your other hand so that the two hands oppose strength. What you are doing is the effect of torque. Torque at high engine speeds theorically should give you better friction, therefore the engine makes more power. These gains are minimal, not more than 10 hp with a really powerful car, maybe a race car, due to the special racing components it works with. For a normal car, say a 4 cyl, the gains would be marginal, but the efficiency is increased. That's why the oild change intervals are greater with synthetic oils. They tested a V8 camaro with initially 302 hp, and after the oil change with royal purple it made 308 hp. That's it. That's all there is to it. But do never say that synthetic oil DOES NOT give you a gain. Whether it is big or not, depends on your engine.
Re: Royal purple = more power???
Aug 24, 2003
22 Replies
Oh my.
A multigrade oil has two numbers on it--say 10W30. They mean different things.
The numbers refer to the oil's viscosity, as we all know. "Weight" in this case is slang; if you were to put a quart of 10W30 on a scale next to a quart of 20W50, there might be a few grams difference between the two but nothing to write home about. They measure viscosity with a Saybolt Viscosimeter, which is a bucket with a hole in the bottom of it. Plug up the hole, put in some oil, open the hole and time the oil as it drains. The longer it takes, the higher the viscosity. Compare the time to a table that comes with the viscosimeter and you'll learn the oil's weight.
The "10W" part is the oil's winter (sometimes called "arctic") viscosity. It's measured at 0 degrees celsius. The viscosimeter is different, with a larger hole than the summer viscosimeter, and the table is different--the times are much longer because you're dealing with a fluid the consistency of honey.
The "30" part is the oil's summer viscosity. It's measured at 100 degrees celsius through a viscosimeter with a little hole in it.
(Having said that, all of which is true, the international standards community has gotten involved. Now it's all in metric, and certified by ISO, but the US table's been jiggered around so that 30-weight oil is still 30-weight oil. Europeans always liked their oil spec'd in Saybolt times; I have a Heidelberg press that lists the oil it needs in Saybolt times. Then you call the oil company and ask for some oil with that special rating, and what shows up? Straight 30-weight Shell Rotella T...with an invoice for $425 for a 55-gallon drum. We buy it at Sam's for $257 a drum now.)
You can go to the store, buy a quart of straight-weight oil and run it through the two viscosimeters so you'll have a "multigrade" oil, but it might be 750W30. To solve the problem, everyone's on the right track: take an arctic oil with one viscosity and add polymers to modify the weight/temp curve.
I remember in my misspent youth running into 20W20 Pennzoil. My dad loved 20W20 Pennzoil in his Chrysler for some reason. Now he's into 5W30 Mobil 1.
Oh, the 0W oil? The arctic table does go that low. Why you'd want oil that thin I have no idea.
--jmowreader a fount of useless knowledge
Better quality oil = poorer lubrication? Dude, quit smokin' that stuff!
If you're minimizing your mechanical losses through lubrication, it would follow that you're getting better lubrication than before. Not worse.
--jmowreader
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