Okay so this is probably a REALLY dumb question but I just want to be safe. In my 1988 RX7 GXL what type of oil should I use. The guy who owned it before said he put in 10w30 conventional, does that sound like its right? I know some people use higher weights but I thought I would keep it the same. I live in the midwest (Indiana) if that helps any. Thank you.

 

Tons of info on this topic, do a search and decide for yourself which is best for your driving style and time of year you drive.

Me personally I use PennGrade (Brad Penn) 20w-50 it has high ZDDP content for bearing protection and makes cold starts a breeze.

in general, use only API SJ or SL at least, most oils now are SN which is reduced ZDDP.

But this is just what i believe, could be totally wrong.

 

the engine likes fresh oil, but other than that it does not care too much.

 

I use Castrol GTX 20w50 in all of my 7's. If I drive them in the fall when it's a bit cooler I will switch over to 10w40 but I don't use anything else. I've used the same brand and weight if oil for over 20 years with zero issues.

 

I've been using Havoline 10w40.

 

It seems everything depends on the temperature of the environment where you live for example if you live in a region where the temperature is like -20 to 20 (F) it is preferable to use motor oil with a viscosity of 5W-30, if it is in a region with a temperature from 15 to 35 (F) you can use 10W-40, if it is from 20 to 70 (F) you can use 10W-30, with temperatures from 60 to 120 (F) you can use 10W-50, you can also use in temperatures from 20 to 70 (F) 20W-40 and from 70 to 120 (F) motor oil with a viscosity of 20W-50. I hope this information helps you.

 

20w50