Do thicker engine oils affect power?

[FunkyR]

Changed from 5W40 to 10W50 at my last service and the response seems a little more sluggish....

Have heard that a thicker oil (ie viscosity) will make the engine rev slower - but all I've heard is theoretical ideas - no real proof.

Anyone know for sure?

[00dc2]

i have heard that too... and that thicker oils will cause your engine to get hotter too..

[B.ITR.00]

I don't have any real proof here but i know with my own experience with oils you need to chose a oil that is suited for your conditions and temp range (racing to normal street driving) or ( northern Australia to Tasmania)

putting a heavy viscosity oil would make it more sluggish when the engine is cold defiantly, though i don't think that it wouldn't make alot of difference when the engines hot

i think making sure you have the correct amount of oil would have more effect due to i see alot of people over filling there engines with oil (more drag on the crank shaft)

where i am in mid QLD i run a 10w40 (turbo light) i tryed the honda FEO 10w30 and it made the sound of Vtec more metallic around 7k - redline. With the turbo ligth its more quite and smooth

i think there has been a big debate in another thread on this forum some where about this. but in the end its more personal preference than any thing, probably be a on going debate or should i say argument lol

[euGeR]

I feel it does. It's more of a drag on your revs rather than a loss of power. I've tried 15-50W and I drained it a week later, it didn't feel like the engine had the same punch - 10-40W is a compromise and the 0 weight oils feels the best but may not have the protection for endurance racing but for us, if we change it regularly, there's no issues

10-40W royal purple feels very smooth

[izy-20]

yes it does affect performance. Just think about it, the oil is thicker than oem so it is going to require a little more force than usual working more than what it has to.

[sinobi]

well guys i am was runing 10-40 but kinda wanted to try simething different. so i used 5-40 i no its dumb of mi to try it in summer but wat the hell. so i did on cold days it worked like a dream but hotter days it it seems like the vtec kicks in later,plus a lost of power with it.
so summer use thicker
winter use thinner
heheheh hope that helps u out
cya

[G_Vtec]

i generally run a thin oil for daily use and switch over to a thicker oil when i am tracking the car.

imo, 15-50 is too thick for everyday use.

[freakygeek]

well guys i am was runing 10-40 but kinda wanted to try simething different. so i used 5-40 i no its dumb of mi to try it in summer but wat the hell. so i did on cold days it worked like a dream but hotter days it it seems like the vtec kicks in later,plus a lost of power with it.
so summer use thicker
winter use thinner
heheheh hope that helps u out
cya

VTEC actuates at a set RPM. This doesn't change when you change oils....

Perhaps you mean that the car feels more sluggish?

[spoondc2r]

I have a question, 0w40 right? the 0 means the viscosity at 0'C and 40 mean the viscosity at 100'C. So it should be able to protect your engine right away?

[milkman]

For me it's:
Summer 10w-50
Winter 5w-40

Refer to your handbook and match it with average ambient temps & use the corresponding recommendations by Honda.

[Page]

I have a question, 0w40 right? the 0 means the viscosity at 0'C and 40 mean the viscosity at 100'C. So it should be able to protect your engine right away?

http://en.wikipedia.org/wiki/Motor_oil

Good read.

[TODA AU]

Changed from 5W40 to 10W50 at my last service and the response seems a little more sluggish....

Have heard that a thicker oil (ie viscosity) will make the engine rev slower - but all I've heard is theoretical ideas - no real proof.

Anyone know for sure?

You can measure the difference on a dyno, & the thicker oils do rob you of a little power.
0W30 vs 15W50 is approx 5kw difference in - DC5 K20A
However the thicker oils give better temperature control.
EG: We use 15W50 oil or better in track engines for this reason.
If you were doing extended stints on the track, a 20W60 would also be an acceptable option.
If you have good oil pressure & temp control, it's hard to run a bearing.

[szymonsta]

great info TODA thanks for the input

[Didz]

i use motul 8100, it's 5w-40 and i think it does the job quite nicely in my dc5. But hey if u get more power from thinner oil i might try it one day but as Toda said, it has its ups and downs

[BlitZ]

damn ... ~5kw difference..

that a fair bit..
Im running 0-30 castrol full synthetic. Will be swapping to 5-50 for track..