Let's clear up a common misconception (oil viscosity)

[PlasticMonster]

Ive read through this and have a well maintained NA. I have just put in 0w 40 castrol rs. However i am now having doubts, should i have gone safe and got the 5w 40?

I was thinking that as im not running a turbo i dont need a heat proof oil (well over 40), and the better start up protection of the 0w would be the best for the engine. Rev 5 Na, induction kit, full free flow exhaust.

[oilman]

If it's a stock car, used on the road and oil temps never exceed 120 degC then a 5w-40 is fine but if the car is modded, used on the track and sees higher than normal oil temps then 10w-50 would be a better choice.

10w is fine for summer and winter but 5w has the edge when it's cold.

Cheers
Guy

[davecarr2000]

If it's a stock car, used on the road and oil temps never exceed 120 degC then a 5w-40 is fine but if the car is modded, used on the track and sees higher than normal oil temps then 10w-50 would be a better choice.

10w is fine for summer and winter but 5w has the edge when it's cold.

I currently use fully synthetic 5w-40 for my Turbo.
Should I change to 10w-50, or 5w-50 for the summer when it gets pushed more.

I still want to use 5w for winter/autumn.
Is it ok to change the grade of oil in this manner?

Cheers
Dave.

[oilman]

No need to swop mate, the 5w-40 is fine summer and winter.

Cheers
Simon

[jonson]

Hopefully someone might be able to answer this little query for me about oil - If Toyota recommended 10w/30 for the REV3 turbo is this no good? I'm currently using 5w/30 fully synth - don't appear to have any problems ie minimal oil burning no smoke etc, or have I just been lucky so far?! Anyone else use a similar viscosity oil? Any help/advice much appreciated!

[oilman]

5w-30 is fine for a stock road car.

Cheers
Simon

[jonson]

Ok Cheers Mr.oilman.
It's not quite stock ie runs a little more boost, & it is likely to get plenty of stick in the summer so maybe a 5w/40 would be better? As the engine's designed to run with 30w oil when warm is there a chance a 50w would be too thick to pass through the oil ways ok? Sorry to mither/pester about this!

[oilman]

Ok Cheers Mr.oilman.
It's not quite stock ie runs a little more boost, & it is likely to get plenty of stick in the summer so maybe a 5w/40 would be better? As the engine's designed to run with 30w oil when warm is there a chance a 50w would be too thick to pass through the oil ways ok? Sorry to mither/pester about this!

The Japs run on 5w-30/10w-30, over here in the uk we tend to use a 5w-40.

The 5w-40 would be fine and would porovide greater hot end protection then the SAE30, however if you really intend to give the car some stick then there will be no harm moving to the 10w-50, it will not be too thick just provide greater protection at higher temps.

Hope this helps.

Cheers

Simon

[www.mr2turbo.info]

Toyota _didn't_ recommend 10W30 for the MR2 turbo, if you check the Japanese owners manual or the UK repair manual for the Celica GT4, they recommended a range of grades depending on what temperature the car was likely to be used in. The lowest recommended cold grade in the manuals was 5W, but whether that was simply because 0W wasnt about when the manuals were written I don't know. The highest recommended hot grade is 50.

Interesting I expected this thread to change my opinion on 0W, but amusingly oilman seems to have a preference for 5W which is what, in my ignorance, I've been using (Valvoline synpower 5W40).

Cheers,

Robin

94 turbo

http://www.mr2turbo.info/

[jonb-]

Halfords have 0-40w castrol at half price and i just bought 5 litres.... I guess it'll do for the next 4000 summer miles

Now if only i can find a guide to changing the oil, i've not got the handbook

[foxdie]

OilMans my hero. I follow him from one forum to the next... Have my babies oilman