I have a 1981 rx7 that I use very little, less than 2,000 per year. I plan on driving it a little more so I need to know what grade oil do I use. The previous owner used 20-50 but someone else told me that was to thick. Tell me what brand and grade to use.

 

Oil viscosity depends on your climate. Suggestions based on the temperatures you see should be in the 1st gen FSM. They're in the 2nd gen FSM at least, and the viscosity suggestsions should be the same. Click the FAQ links at the top of this section.

 

20w/50 is typically used in diesel engines or by scumbag salesman trying to conceal oil burning problems. You're in a colder climate and you will need to use the thinner of your oil options if you start the engine in the winter.

I'd say that most important of all is to make sure that you drive the car for 30+ minutes if it's rarely started. Condensation and the resulting water mixing with oil isn't good for business, and the extended drive effectively "burns" that off. Check the bottom of your oil cap (or catch can, if you have one) and see how nasty it gets.

 

The 20W50 grade would work great... if you lived in Florida.

For your area you will probably want to use 10W40 or 5W30. As explained earlier, just look up your area's temperature range in the manual to see which grade is recommended.

As for brands, Castrol GTX works well in rotary engines.

 

Sorry to hijack, but using a thicker oil provides no extra engine protection of any kind?

 

In general, thicker oil provides better high-temperature protection. Unfortunately, thicker oil tends to cause more wear at lower temperatures. Thicker oil also reduces horsepower and gas mileage.

 

I use 5-30 cashroyal gtx and I live in california.
is that okay?

 

Correct. I'd like to add that it basically means that thicker oil is more suitable for racing applications (namely, high temp). It's not adviseable to use thick oil in cold climates because of the lack of viscosity and resulting wear on the unoiled components of an engine (oil moves down with gravity when the car is parked).

All the oil info you can imagine: http://www.bobistheoilguy.com/forums/ubbthreads.php

And if you're curious what happens to engine oil at very cold temps: http://www.youtube.com/watch?v=gKtxqf5OFTU

 

Sounds like my 20w 50 is overkill for Northern california then, ill drop back to 10w 30 and give that a shot.

 

http://www.ferrarichat.com/forum/faq...=haas_articles

 

Castrol 20/50 Seattle. Never have had any problems. But may switch over to Royal purple synthetic in the tranny and rear end this summer.

 

I live in FL and I use 5w-30 royal purple. my personal favorite is synthetics, so Mobile 1 or royal purple are probably your best bets.

 

I use for my FC turbo, 10-40 Royal Purple for normal driving, and 20/50 Idemitsu for track. No problems yet.

 

I'm curious how would motul or eneos work in a engine?

 

In the '83 FSM Mazda recommends
20W-40 or 20W-50 for above 15 dF
10W-30 for -13 dF to 86 dF
10W-50 or 10W-50 above -13 dF
5W-20 below -4 dF
5W-30 below 32 dF

 

umm, do you guys realize this post is well over 1 1/2 years old??? i use 20w50

 

I have been told by a 30+ year rotary builder, that unless you live in freezing temps, ALWAYS use 20w-50 in a rotary. I have been doing so for 7 years now here in northern California (worst day of the year is 35-40 degrees) and have never had a problem.

 

I use 10-30 high mileage. never had a problem

 

20-50 here... per fsm ill be using it unless we get a good cold winter here in va

 

What oil Should I use at the track with excess of 100 degree weather?