Oil affect BHP??
 

I've been reading up about types of oil (sad I know) and came across an article stating that your choice of oil could improve you BHP.
Something to do with the viscosity when the temperature changes.
Anyone else come across this and is there any truth in it outside of lab conditions:wonder:

At least I know what SAE stands for and what 10w50 means now:lol1:

Sadly I have to do the same from time to time :)

Yes, using certain oils can increase bhp in two ways - reducing internal friction and reducing resistance. Some oils are better lubricants than others, so they reduce the friction. Thinner oils reduce the resistance.

Silkolene did a test a while back, using Honda Blackbirds and their Pro S and R oils. There was an increase of about 6-8% (if I remember correctly, the data is on my other computer) betwhen the oil was changed from Silkolene Pro R 15w-50 to the Pro R 0w-20. As those are basically the same oil, just in different viscosities, that shows the increase in just reducing viscosity. I'd generally only advise using 0w-20 in race engines that will be rebuilt on a regular basis as it's not used for protection, just enough to stop the engine seizing. One of our sponsored drivers races in a Mini cup, no modifications allowed, so he uses 0w-20 for an extra couple of bhp.

Cheers

Tim

I might have guessed you'd know :D

That reminds me, I need some Millers CFS....

Something I meant to mention above is to ignore all the oil tests that are on Youtube etc that show how amazing their oils are. There's one which shows something like a 10-15% power increase just from changing the oil and they say that's just because their oil is amazing and their tests prove it. Load of rubbish. Their oil may well be good, but they don't tell you what's in the car in the first place. Something like a dirt cheap 20w-50 mineral oil in a modern engine is going to make it run a lot less efficiently than it should.

I just found the article about the Blackbirds, with the information coming from John Rowland of Fuchs/Silkolene.


He place to look for extra power is in that 6% lost as oil drag. In a well-designed modern motor, the oil doesn’t have to cover up for wide clearances, poor oil pump capacity or flexy crankshafts, so it can be quite thin. How thin? Well take a look at these dyno results.

A while ago now, we ran three Silkolene performance oils in a Honda Blackbird motorcycle. this fearsome device is fitted with a light, compact, naturally aspirated 1100cc engine which turns out 120+ bhp at the back wheel. The normal fill for this one-year-old engine was 15w-50, so the first reading was taken using a fresh sump-fill of this grade. (The dyno was set up for EEC horsepower, i.e. Pessimistic)

15w-50
Max Power 127.9 bhp @ 9750 rpm
Torque 75.8 ft-lbs @ 7300 rpm

After a flush-out and fill up with 5w-40 the readings were;

5w-40
Max Power 131.6 bhp @ 9750 rpm
Torque 77.7 ft-lbs @ 7400 rpm

Then we tried an experimental grade, 0w-20 yes, 0w-20! This wasn’t as risky as you may think, because this grade had already done a season’s racing with the Kawasaki World Superbike Team, giving them some useful extra power with no reliability problems. (But it must be said, they were only interested in 200 frantic miles before the engines went back to Japan)

0w-20
Max Power 134.4 bhp @ 9750 rpm
Torque 78.9 ft-lbs @ 7400 rpm

In other words, 3.7 bhp / 2.9% increase from 15w-50 to 5w-40, a 2.8 bhp / 2.1% increase from 5w-40 to 0w-20 or a 6.5 bhp / 5% overall. Not bad, just for changing the oil! More to the point, a keen bike owner would have paid at least £1000 to see less improvement than this using the conventional approach of exhaust/intake mods, ignition re-mapping etc.