Sorry but its Engine Oil [again]
 

Guys,

This is probably the oldest question on the RX-7 forum but I have to ask it as I am new to the FD and it does not appear, to me, to be a settled question !!

My car is a 94 Type R ..... what type of oil should I use ??

Now I have heard that a good Non Synthetic is best but I see posts that refer to Synthetics being used, what do I choose.

Once again sorry for the BASIC nature of this question, I hope my enquiries will get a little more interesting down the line.

John Helps

Everybody's got to start somewhere, so dont feel bad about posting anything youre not sure about. As for as oil, synthetic is not much more than a waste of money for a street car. It can cause the dowel pin O-rings to leak, which while it wont hurt anything, will be very annoying. Also synthetic desnt burn as well. The 2 most used oils are Castrol GTX and Valvoline Racing VR1. Weight for turbo's should be 20W-50, while n/a's should use between 10W-30 and 20W-50. I use Valvoline VR1 20W-50 in my 90 GTU and 84 GSL.

Thanks
 

Thanks Adam

I take it from your list of cars that you have been "With Mazda" for a while and that youre reply is more or less the general consesus.

Im importing my Type R, its still in Japan should be here for Xmas and the guy putting synth in was the previous owner.......NOW IM WORRIED, but informed.

L8R
John

There is somehting about synthetics, wherein once you use them u cant go back to dino oil. I forgot what it was, but it was on conventional engines, so for all I know it might not be the same on the rotary. But it's something to research and be aware of. There are plenty of people that run synthetics on their FDs and report no problems whatsoever.

Hi Nameless & list,

Yeah, thanks for that I thought that might be the case, that many also use synth. and dont have problems.

I see it like this, the previous Japanese owner of my car had enough judgement and "class" [dont like that word but cant think of a better one jut now] to fit Ohlins suspension and 18" Volk rims. So anyone with those credentials knows about the oil question and has weighed it up. There is an alternative point of view......do you Nameless, or does anyone out there know what Mazda has to say about this ??

John

I have the same dilemma and problem. I just purchases a mint 89 convertible with a factory new engine, and the original owner put in synthetic oil howver claimed he changed it every 3k. I was wonderrinf the same thing about the synthetic oil, should I be worried? And like you I have read and heard mixed opinions. BUt from what I have read and heard, mazda recommends against using synthetic oils... WHO KNOWS!!!!

Well thanks Myron96,

Was that Mazda recommendation in a handbook ??

If so thats good enough for me .......... in that case I just cant understand anyone using synth......

Oh well "you pays your money and you takes your choice"....

Is no one going to put the case FOR synth oil......

If not I guess the subjects pretty much dead.

Thanks everyone who contributed

PS My car is on its way from Japan ...it goes on the boat this week- thursday and arrives around Xmas ........guess I'll get my hands on it by 2002 ...its a '94 Type R

John

Mazda recomends against synthetics because they don't burn as well and hence lead to excessive carbon build up around the apex seals. on a practial side synthetics don't really provide much benefit for a rotary because they have to be changed @ 3000 miles just like conventional oils but they cost 2-3 times as much
Caxtrol GTX 20-50 or 10-30 is my choice - I also add 1 QT Marvel Mystery oil at each change

Also 99% of the synthetics on the market are fully compatible with conventional oils - they can even be mixed.

Thanks for your comments .........especially the bit about mixing oils as the previous owner of my car has been using Mobil 1 every 3000 mls and of cousre I will not be, i've chosen Valvolene to put in the car when it arrives.

John

Can anyone advise if there is any special procedure when switching back to mineral oil? Or can i just replace the synthetic with the mineral oil.

Racing Beat recommends synthetics - namely Royal Purple 10W30 - 20W50. They claim it burns free of carbon and deposits thus doesn't coat the apex seals with any unnecessary junk. It's supposed to make the motor run cooler (less friction) which is always a good thing. I'd say close to half the FD owners on this forum run a synthetic without any problems. Do a search for "synthetic oil" on this forum and you'll find plenty of information. Hope this helps.

oh and on another topic... don't mix synthetics with dino. It's probably true that no harm is done the majority of times. I do have personal experience running a synthetic in a Yamaha YZF-R6 (sportbike) and then switching over to a dino oil. The one time I had someone else change the oil (laziness kills) the mechanic dumped in dino oil. The remaining synthetic and dino oil formed a thick sludge causing my motor to seize. When I took the bike to Yamaha for them to look at they told me to never mix a synthetic with a dino without first running a bottled 50/50 semi-synthetic.

Hi dhg11 & list,

Sorry its probably just my Londoners bias buit what is a dino oil EXACTLY ??

Mineral oil ????

Like GTX or similar

John

Who's right, Mazda or Race shops?
 

The Race shops recomend Red Line.
Racing Beat Recomends Royal Purple.
(Both of those are synthetic)
The factory Mazda RX-7 owners manual has a warning "not" to use synthetic?

Rotary engines are twice as hot as stupid engines, so synthetic would make sense.

If synthetic's clog up those seals or whatever, then that might explain why i'm leaking oil after a new engine...uhg.