I have a 1990 celica st185 gt4 I want to do an oil change but not sure what oil to use, its done 159.000 miles can anyone help??

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I've always used Mobile1 fully synthetic. You can feel a noticeble smoothness to it over regular dinosaur-oil.

10w-30

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exellent mate thanks for that will buy some tomorrow

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will see if they do mobile 1 oil in 10w-30 thanks mate

I use 5w/30 fully synthetic oil for mine.
But your being a turbo engine, I would
go with something thicker.
If you have castrol over there, I'll recommend that

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we get castol in uk will see which is cheaper, thanks mate!

I know Castrol Syntec is usually cheaper than Mobil here. I used to use Mobil 1 synthetic and it was a huge difference in smoothness over "dinosaur oil". Now I put in Castrol Syntec just because its cheaper, and the bottle is a little easier to pour.

Really any synthetic is great, but if you can afford it get Royal Purple. Its supposedly lightyears beyond anything that petroleum companies selling synthetics are making....much more durable and protective.

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never heard off royal purple but will have a look around and see how much it is!

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I have never heard of royal purple but will have a look around and check it out!

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I am an engineer who designs lubrication systems for a living everyday and I will say this:
Royal Purple is the only oil we do not reccommend and will void our warranty. The seals used in our systems are automotive engine seals and the royal purple attacks them - especially on older seals that are used to regular dino-oil. My educated .02 - stay away from Royal Purple - the benifits are not worth the risk.

BTW - my 4th gen swap loved M1 15w50 for the turbo engine. just don't use it on newer engines - stay with 10w30 or 10w40 would be even better. Turbos need thicker oil as they cause the oil to break down faster. or just more frequent oil changes which costs more.

This post has been edited by Negative: Apr 10, 2006 - 11:22 AM

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lucky you told me that I shall give that a miss! and stick with somthing else! thanks

well if you can afford it REDLINE is a great synthetic proved a 25whp gain in a WRX....just by using all redline fluids over stock

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will check up on prices for that always up for an increase in power! cheers!

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That's awesome. I may have to look into that both for my company and my car. How was it proven.

it was proven via dyno test...base run was stock off the lot
next run was all fluids (crank, tranny,ect..) replaced with redline then re-ran on the dyno

7.5 hp on a 500+ hp car? That range is within the difference you would get between dyno runs with NO changes. BTW, where is the source of that information?

Here is a link for you:

dyno testing different oils

Notice that the primary differences depend on oil weight. They only tested a 20w-50w mineral oil and 9 different synthetics. Simalarly weighted synthetics showed about a 4whp difference - about 1% and within the margin of error of the dyno.

There are VERY good reasons to use synthetic oil. Gaining horsepower is not one of them.

This post has been edited by jgreening: Apr 11, 2006 - 12:37 PM

http://www.bits-pieces.com/pages/whyredline.html

thats 8 hp on the same 30wt oil...
i'm not saying this is going to get you 25whp on your celica....you could probably come away with 4-5whp maybe....but thats 4-5 i'd take...


This post has been edited by playr158: Apr 11, 2006 - 12:46 PM

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On MY Celica? 0-3 whp. On the average 6gc, 0-1 whp.

Its my opinion that the 25whp figure even for a high powered AWD vehicle is simply not accurate unless they were comparing different weight oils. However, that point notwithstanding, your initial post about the "25whp" does not indicate to the uninformed reader who owns a 6gc that there is no way in hell he can expect anywhere near that kind of gain in his own car. In my opinion, it implies the opposite which is VERY misleading.