DrEvil

Ok, I'm about to change engine oil for the first time (in my 1988 RX7 turbo that is).

The previous owner told me that the used Penrite HPR30 which is 20W-60 mineral oil. Just to make sure, I went to Penrite website where they recomended HPR10 instead, which is 10W-50 semi-synthetic oil. Valvoline recommends their 20W-50 oil for the same model. Then, I have read somewhere that most people use 10W-30 oils. Someone also told me that I won't get much benefit out of Castrol Magnetic GTX2. Boy, I'm really confused now. Which one should I use?

I know that synthetic oils are a no-no in rotaries (don't burn or don't burn clean). Similarly, isn't 10W-30 a bit to thin specially in summer? I thought rotaries run more hot, so the higher summer rating of 50 or 60 would help?

I live in Canberra, Australia where temperatures rarely go into freezing (nothing like in the US) but summers can be hot. Would anyone from OZ suggest what grade to use?

Much appreciated,
D.

trainwreck517

iTrader: (1)

depends on temp, I currently have 20-50 but I see about 70-80F durring the winter.

MountainTurbo

I would run 20w50, especially if it gets hot where you are.

Also, you CAN run synthetic, just not cheap synthetic. The nicer synthetics many times actually burn cleaner than mineral oils (but they're usually pretty pricey).

Icemark

I personally do not ever recommend 10W40 or 10W50, just because of all the additives and polymers that have to be added to get that range on a 10W base stock.

And search on the Synthetic thing. Mazda simply says no synths because there are a lot of crappy ones out there. A good synth is perfectly fine to run and will have lower deposits, and more HP and engine protection than any conventional oil. As covered countless times, in countless threads here (heck I was going through some old RX-7 reports from the late 80's today as well as several SAE papers from the same time... and they all proved back then that synthetics oils like Redline and Amsoil worked better than conventional oils when used in a rotary engine and drive train.

andrew lohaus

sounds like your climate is like florida. go with castoral gtx 20w-50 all year round, cant go wrong if you still have the stock oil injection. if you have eliminated the oil injection go with a 20w-50 synthetic. my onp is out so i think im gona go with either 15w-50 mobil 1 or the equivalent royal purple oil (yeah they sell it just up the street from me!)

bingoboy

if you leak oil from anywhere, synth will be sure to leak more. for an area with a warm/hot climate, 20w-50 is the way to go. i use castol gtx 20w-50.

RHDturboII

iTrader: (4)

I used to use Castrol GTX 20w50 all year long but now I use Castrol GTX 15w50 due to the fact they started discontinuing the GTX 20w50 here where I live.

SpeedFreak03

My vote is 20w50 I think for warmer climates like yours that is the best for you. Good luck!

Froggmann

I run 20W-50 Castrol GTX here in so Cal and am quite satisfied with it. It looks to burn a lot cleaner then some of the other crud I've had to put in Baby and my oil pressure stays a little more constant.

lake snake

I had been running Castrol GTX 20-50 last summer, but when it got colder this winter I had zero oil pressure on startup once and I freaked. The starter was turning slower so I went to 10w40 then found the starter brushes were worn down. After rebuilding the starter everything was back to normal so I'm going back to 20w50 at spring oil change(weekend driver only 2K on her last year)

motto

No Brianer, Castrol GTX 20-50W

Wankels-Revenge

I use 20W-50 here in toronto..and its an n/a

rxse7en

I resent that comment!

Brian

IRISHMAN

20-50W VALVOLINE V RACING SOUTH FLORIDA

vrooom305

Yeah I kinda noticed a drop in performance when I used 10W-40. 20W-50 all the way!