What motor oil should I use in my 7MGTE? (I ask after reading all sticky threads)

[VegaSupra]

I don't want to be 'that new guy' that asks a bunch of annoying questions because he's too lazy to read the threads where the question has been addressed 33 times already. So I read through all the sticky threads int eh oil section and the first 2 pages of other oil threads and still wonder one simple basic question...

What specific oil should I use?

Based on all the tests people did with Blackstone, it seems MKIII owners have great success with German Castrol, but several like Amsoil too. Royal Purple seems iffy, but I am surely open to anyone's testimony of success using RP.

Some basics specific to me:

I live in San Diego, CA - so it's never freezing here and usually quite warm.

My car: 1991 Supra Turbo - 5spd - 68,000 miles. 7M-GTE. Owner has used synthetic since the 2nd oil change. I don't know what kind of synthetic, meaning I don't know if it was group 3 or group 4/5 but I suppose I could find out.

Here is what I'm thinking (without running any specific tests on my oil).

Use either Amsoil or German Castrol 5w30 every 7-10K miles and I should be in good shape.

Am I off base with that mentality?

Thanks very much!

 

[jetjock]

That'd work although I wouldn't go the full 10K unless the engine is in good shape and that run is mostly highway miles. Truth is any decent Group 3 and all Group 4 will do the job. The first thing you need to learn about oil is to stop fussing so much over it...

 

[Suprapowaz!(2)]

TSRM's recommended viscosity is 10w-40 & 10w-30 from 0 to 100+ degrees. 5w-30 from 50degrees and under. Under normal driving conditions they recommend changing your oil every 5000 miles or 6 months. Change your oil filter every 10000miles or 12 months.

Of course this was printed back in the late 80's early 90's. But that's what Toyota recommended at the time. Can you go wrong with that?

 

[jdub]

You can go wrong with that precisely for the reason you stated - the manual is over 20 years old. Oil formulation has come a long way since.

Vega - you won't go wrong with German Castrol, and you won't pay Amsoil's inflated price. GC will go 7-8K easy, just change the filter at mid-mileage and add make-up oil.

 

[Suprapowaz!(2)]

Yes, oil has come a long way since then. I wouldn't go as far as going too thin on the viscosity though. Even castrol has a general breakdown of the different grades of oil and recommended use of each on them. http://www.castrol.com/castrol/genericarticle.do?categoryId=8264018&contentId=7007302
Plus I would think that the 7m engines clearances were designed for the thicker viscosities. Newer engines today may be running very tight clearance which may require a lighter viscosity. Oil has come a long way since the birth of the 7m, but the 7m clearances have not.

I've seen too many threads of "I suddenly developed a rod knock after oil change", and alot of those threads have something in common. Guys running 5w-30 or lighter synthetic oil. I don't think the old 7M likes it. That's just my opinion, and I'll stay away from the lighter stuff. Im running Castrol GTX 10w-40. I'll stick with that.

 

[jdub]

Yes, oil has come a long way since then. I wouldn't go as far as going too thin on the viscosity though. Even castrol has a general breakdown of the different grades of oil and recommended use of each on them. http://www.castrol.com/castrol/genericarticle.do?categoryId=8264018&contentId=7007302
Plus I would think that the 7m engines clearances were designed for the thicker viscosities. Newer engines today may be running very tight clearance which may require a lighter viscosity. Oil has come a long way since the birth of the 7m, but the 7m clearances have not.

I've seen too many threads of "I suddenly developed a rod knock after oil change", and alot of those threads have something in common. Guys running 5w-30 or lighter synthetic oil. I don't think the old 7M likes it. That's just my opinion, and I'll stay away from the lighter stuff. Im running Castrol GTX 10w-40. I'll stick with that.

What in that link supports your "opinion"? I see nothing that says a 0W or 5W-30 is "too light".

If you are going to have an opinion, at least base it on the facts. Saying a lighter weight oil is a factor in rod knock completely ignores a much more in common and far more frequent factor - a blown head gasket that has caused coolant to contaminate the oil. if that happens, it doesn't matter what kind of oil it is - if the engine is run with coolant in the oil (and you likely won't know it), the bearings will rapidly FUBAR.

And, what makes you think 7M bearing clearances were designed for thicker viscosity oil - more opinion? Never mind look up engineering specs, opinion is all important. I'll give you a clue - the 7M and JZ engines were designed to use a 30W multigrade with the engine at ops temp. If you want to use a thick oil, especially a 20W-50, you need to open the bearing clearances up a bit to allow good flow - plus, a few other things to the oil system. Higher viscosity = reduced fluid flow - physics is a real bitch

If you are saying German Castrol is a "light" weight oil, you have obviously not looked at it's specs - at ops temp, it's viscosity is very close to a 40W. You might want to do a little reading before you respond - so far, what you've said is displaying a good deal of ignorance of how motor oil weights are determined and how it works in an engine, especially concerning it's flow. If you want to debate me, I highly suggest you at least read the stickies (like the OP) and read Motor Oil 101 in my sig...at least you'll have the basics.

 

[dmp316]

I am in Miami,fl so it is hot as hell here too. I use Mobil 1 10W40 syn. Since i have read so many places that the 7M is oil greedy 6 quarts and now problems what so ever.

 

[Suprapowaz!(2)]

I'll just stick with what toyota has recommended 20 years ago for a 20 year old car. No doubt motor oil has advanced in the last two decades, but that doesn't get me excited enough to pay more for it.

 

[jdub]

I am in Miami,fl so it is hot as hell here too. I use Mobil 1 10W40 syn. Since i have read so many places that the 7M is oil greedy 6 quarts and now problems what so ever.

I've lived in Miami and now live in Phoenix..you have no idea of what hot summers are really like

Mobil 1 is a Grp III hydrocracked base stock - it's not even a true synthetic. I use German Castrol, a Grp IV PAO base stock - FYI, only Grp IV and Grp V bases stocks are real synthetics. It's marketing that calls a Grp III a synthetic, not the engineers.

Suggest you also read the stickies and Motor Oil 101

I'll just stick with what toyota has recommended 20 years ago for a 20 year old car. No doubt motor oil has advanced in the last two decades, but that doesn't get me excited enough to pay more for it.

Where does it say in the manual that a 10W-40 is recommended? It shows what's allowed, but there are no recommendations for a specific weight oil. If you want to use 20 year old info and extrapolate to a modern oil, have at it. Ignorance is indeed bliss

Me? I'm going to base my opinion on specs and hard facts. Keep in mind ignorance is curable, stupidity is not

 

[Poodles]

I am in Miami,fl so it is hot as hell here too. I use Mobil 1 10W40 syn. Since i have read so many places that the 7M is oil greedy 6 quarts and now problems what so ever.

Miami has nothing on Texas, and I run German Castrol... Also, Mobil 1 is a ripoff for what it is.

 

[Suprapowaz!(2)]

Where does it say in the manual that a 10W-40 is recommended? It shows what's allowed, but there are no recommendations for a specific weight oil. If you want to use 20 year old info and extrapolate to a modern oil, have at it. Ignorance is indeed bliss

Me? I'm going to base my opinion on specs and hard facts.

Well, I don't have my original manual. Only going by what TSRM has printed. I just read Motor Oil 101, and it makes perfect sense. You're right though.... ignorance is bliss.

 

[jdub]

Using a 10W-40 is not necessarily bad - like JJ said, you can fret over this stuff to an extreme - any Grp IV or V oil will work fine. Even the advanced Grp III hydrocracked oils (Pennzoil Platinum, Castrol Edge, Mobil I, etc) will do just fine as well - hydrocracked base stocks have advanced to the point where there is little difference compared to Grp IV and V. What torques me is that companies are allow to call a Grp III a synthetic and sell as such - that's marketing BS, pure and simple.

FYI: By definition, a Grp IV is PAO based - a Grp V is all other synthetics, what you see are the ester based oils. Grp V is far less common due to the expense in making it - Redline is the most common, a Grp V ester based oil.

If a motor has a lot of miles, a 10W-40 just might be what you want to use - a 5W-40 would be a better choice IMO for the reduced cold start viscosity. One thing to also keep in mind is the manual and TRSM lists oils that were available at the time - the 0W and 5W multigrades were a rare bird back then.

I'm glad you got my point - making an informed choice is far better than listening to opinion

 

[Suprapowaz!(2)]

I'm glad you got my point - making an informed choice is far better than listening to opinion

And knowing is half the battle.

 

[CyFi6]

What torques me is that companies are allow to call a Grp III a synthetic and sell as such - that's marketing BS, pure and simple.

But does it really matter? If you are willing to pay ex. 6 dollars a quart for a quality oil, what difference does it make where it came from? Are you paying for the process or are you paying for the final product? All I personally care about in the end is that it is a good quality product. Perhaps if they raised the price of group IV/V oils rather than lower the price of group III oils, it would make us feel better?

 

[VegaSupra]

So although San Diego is no Phoenix, we still see temps north of 100 every summer, and rarely see below 45F at any time of year. I have never checked into Amsoil's prices, but I don't particularly feel the need to lay down my money for a companies percevied image value when another company has a similar quality product for less bread.

I'll probably go for GC. So should I run 5W-30 or 10W-30 or does it not even matter? I'd reckon that I could stick with one weight year round, given the reasonably smallish temp ranges that I see in San Diego.

Thanks for your help everyone, and thanks for all the good info jdub.

 

[VegaSupra]

I am looking for German Castrol and it looks like my local Autozone carries it. But I only see 0w30. Is that the only variety it comes in?

Also, it's named "Castrol Syntec" right? Sorry if these seem like super noob questions. I just want to make sure I get the right oil. If 0w30 is the only option, is that what I should run my 68K mile Supra with in San Diego?

thx

 

[CyFi6]

Ya 0w30 is the only variety of German Castrol fully synthetic, just make sure it says "Made in Germany" on the back. Because even a 0wXX oil is "too thick" when cold, a 0wXX will always be a better choice than a 5wXX 10wXX 20wXX etc. even in the hottest of weather.

 

[jdub]

I am looking for German Castrol and it looks like my local Autozone carries it. But I only see 0w30. Is that the only variety it comes in?

Also, it's named "Castrol Syntec" right? Sorry if these seem like super noob questions. I just want to make sure I get the right oil. If 0w30 is the only option, is that what I should run my 68K mile Supra with in San Diego?

thx

GC is labeled "Syntec" - it should also say "European Formula" on the front. As mentioned, it comes only in a 0W-30 and (most important) says "Made in Germany" on the back.

 

[suprastroker88]

I live in the East Bay area of nothern california. I just put about 2000miles on my fresh motor and I want to go synthetic. Redline and GC are the most common in the stores around me. I was looking more towards Redline. Is one better than the other?

I have NPR pistons, Clevites, AZ performance pump pipe, and a shimmed oil pump. What weight Redline or GC should I use?

 

[jdub]

I live in the East Bay area of nothern california. I just put about 2000miles on my fresh motor and I want to go synthetic. Redline and GC are the most common in the stores around me. I was looking more towards Redline. Is one better than the other?

I have NPR pistons, Clevites, AZ performance pump pipe, and a shimmed oil pump. What weight Redline or GC should I use?

Re- read this thread. Then read Motor Oil 101 in my sig.