bigbobballsacks

is castrol edge 0w-40 engine oil ok for my 94 single turbo rx7?

IRPerformance

iTrader: (41)

Too thin in my opinion.

cewrx7r1

iTrader: (2)

0w-40 mean 0 for very cold cranking but 40 when hot.
It is not thin except at cold temperatures.

zack4173

iTrader: (3)

as far as I know 0w40 is meant for European cars.

1QWIK7

iTrader: (33)

This.

I know honda race cars swear by this now.

Honda track cars in japan i mean. ENEOS 0w-20. And all that other crazy stuff.

bajaman

I would listen to this man.

The modern zero, ten, and twenty weight engine oils are designed with the extremely close tolerances modern engines have. There was an article in Car&Driver/Road and Track/MotorTrend that discussed this a while back. And while there were some exceptions, the basic premise was indeed, "These oils are too thin to use in engines not specifically designed for them".

wstrohm

Mazda recommends 10W-30 (mineral oil only, no synthetics) for temps above -10°F, and also 5W-30 if temps are always below 32°F. I have always used Castrol GTX 10W-30 in our '94; still on original engine with good vacuum, good power, and reasonable fuel mileage at 100+Kmiles. (FWIW, personally I wouldn't go below a 10W-xx in this engine.)

Sgtblue

iTrader: (16)

And that's before the varying degrees of fuel dilution that we have between changes.

Sideo

0w30 5w30 10w30 and 30 are all the same thickness. it is not that older engines were not made for these oils, it is that technology did no allow to create them. 30 weight is alot thicker at room temperature yes but why would u want the oil to be extra thick at room temperature. all is doing is fighting the engine until it reachea temperature and thins down.

read the article on ferrarichat form on oil for more info

to OP:
synthetic oil doesnt burn as clean so unless your omp is eliminated its noy reccomended

1QWIK7

iTrader: (33)

Please dont confuse the OP or start another dino vs syn oil debate.

Lots of people here are using syn oil with no problems and have a WORKING OMP.

In fact, im about to switch to royal purple my next oil change. And i have the stock OMP.

no_more_rice

+1....see my UOA thread, oil in these engines loses one or two viscosity grades in < 1,000 miles....no way I would even consider using 0w-40 in a turbo rotary, and I don't consider synthetics to be worth the investment because the OCI is so short (generally 2000 miles)

I'm running Valvoline SAE 60 Racing Oil right now (straight petroleum), I'll let you know how it looks after 2000 miles of turbo thrashing and 6-8% fuel dilution

no_more_rice

Everything is driven by increasingly stringent gas mileage standards, the manufacturers don't care how hard you may be pushing your engine.

For a street driven car that is never pushed that hard and sees little contaminaton of the oil, 5w-30 or 0w-40 is fine. It's simply the wrong application for a turbocharged rotary which subjects it's oil to ungodly contamination and high shear. I've run 5w-30 in the S2000 before and the analysis looks great; I've also seen members in s2ki run 0w-40 with no issues.

1QWIK7

iTrader: (33)

Yeah, im using the basic castrol gtx 10w-30 and so far i put like 900 miles and the dipstick reeks of gas. Not terrible but since im driving the car more, i notice it more.

And im only in 5 weeks since last oil change.

Should i change it at 1500??

no_more_rice

If you're running 10w-30 I would change it evey 1,000 miles. Send a sample to Blackstone Labs and see how it looks, it's only about $20-25.

Since you already know you have fuel dilution (and all of these cars do) you may as well start running a straight 50 weight, because you can bet it's going to have the viscosity of a 30 or 40 weight (or less) within a few hundred miles.

1QWIK7

iTrader: (33)

Yeah i def want to send a sample of my oil. Just for the mere fact im driving the car more and im curious to see what the deal is.

Guess its time for another oil change this weekend lol. Even though usually i would have been due for almost another 2 months lol.

I was actually thinking of switching to royal purple 10w-30 next oil change.

Cost is irrelevant to me but i was wondering if you think the properties in RP would be suffice compared to going with a straight 50 weight of so and so brand, IE valvoline??

Again, cost is not a big deal for me. Im talking about in the 2 oils' properties only.

no_more_rice

Synthetics will perform slightly better with fuel dilution, but above 4% it doesn't really matter, all of them thin significantly. I ran Amsoil 20w-50 in my car, which is one of the better synthetics out there, and it still thinned out of spec (< 10 cSt, should be at least 12.5). Viscosity is what cushions your bearings under load. I'm a believer in synthetics for most applications but this engine contaminates oil so fast it's just not worth the extra $$$.

1QWIK7

iTrader: (33)

Thanks for the advice.

I just ordered my sample kit from blackstone.

I will try RP this weekend just to see how it affects the car. Idling, oil pressure, temp etc.

I dont ever do 3k miles in a 3 month period so i wont care if RP breaks down in 3k. I will prob do about 1200 max in a 3 month period.

I just want the best oil i can get in that 3 month period of use. Or 1200 miles.

no_more_rice

RP usually doesn't fare all that well in used oil testing (compared to Amsoil, Mobil 1 EP, Penzoil Platinium, and Valvoline Synpower) - look forward to seeing your report

1QWIK7

iTrader: (33)

Well really im gonna be testing whats in the engine now (castrol gtx 10w30). Blackstone says takes 2 weeks for the kit to come in. Im thinking if i should wait til the kit comes to drain the oil (should be at about 1200 miles by then) or change it this weekend which is at 900 miles.

Since 90% of my oil changes since i owned the car had castrol gtx in it, i want to see the results of the test at about 1000 miles etc.

Cause if it shows normal results, ill just stay with castrol gtx and change every 1200-1500 miles whatever.

If not, then ill stay with RP, or whatever is out there. But i already bought the RP cause i was soo anxious to change the oil because of all these oil threads LOL