ok i know there was a really big post about this but for some reason i cant find it...so what is the best oil to use in my 88 rx7 turbo???

 

Castrol GTX 20w-50. 6 quarts per change.

 

and what about 87 na?

 

Same oil, not sure on capacity.

 

Pretty sure its the same amount.

 

I just changed the oil in my 87 NA using Castrol GTX 10w-30. It took 6 and a half quarts.

 

Question covered in FAQ. API certified oil or one of the synthetics listed in the FAQ. A synthetic will withstand more abuse (track use, for example), but it's pricier. But if not abused, any API dino oil will perform wonderfully. Both 20w50 and 10w30 will work great most anywhere. Do not use 20w50 if you'll frequently be below 20F. You'll starve your engine for oil every time you try to start up with that molasses in the sump. Do not use 10w30 if you'll frequently be above 80F. I dunno why.

Castrol GTX is popular for having plenty of sludge removing detergents. All oils have at least some detergents. Most synthetics have a lot.

I use 10w30 Royal Purple synthetic in my N/A b/c I figure the 0.4mpg saved will make me break even on the extra cost after 7,500 miles. And if you check the proper recommendations, 7,500 miles is very conservative. For everyone with 3,000 miles stuck in their head, I'd get a good dino oil; the extra cost isn't worth it. Unless you autocross or boost a lot.

 

then let me explain:
>80 degrees F makes 10W30 too thin for proper lubrication
<20 degrees F makes 20W50 too thick for proper lubrication

 

Yeah, I know. It's the 10w30 part I don't understand. I mean, don't you have an oil cooler thermostat fixing your oil temperature no matter where you are? And isn't that much hotter than the hottest desert? I would think it would only hurt to use a thick oil on a freezing cold day before warmup. Not that I'd try to use 10w30 in a super hot region.

 

well i live in georgia...so im guessing i should use the 20w50???

 

^^^ That'd be your best bet

 

A quick wiki revealed that temps in Georgia are relatively mild. Though the highs do average a little over 80F 4-5 months out of the year. So take your pick, either weight will do. 10w30 is more slippery, for less friction, better mpg, less wear, etc. 20w50 is thicker for better coating, better sealing (especially against boost), slower leaks (if you have any), higher oil pressure (again, if you have leaks), etc. I've heard 10w30 recommended on N/A and 20w50 recommended on turbo, probably for the sealing reason.

I'd flip a coin on the oil, buy a Haynes manual, and worry more about the other 50+ maintenance items listed besides motor oil.

 

Freakin faq.

 

15W40 Low Ash Shell rotella works nice. Lower viscosity oil circulates faster than 20W50, but 20w50 is great for high temp (turbo) usage.

 

i got a haynes manual. thanks for everyones help.

 

Mobile 1, 15W 40 is what I consider right for my local (Florida). It is very hard to find. I bought a few cases and haven,t shopped for it latley, However, I don't see it ont the shelves anymore.

 

I use Amsoil 20-50. I have one more gallon then I will switch to Amsoil 10-30.

 

Rubbish. 20w50 year round.

 

i just bought castrol syntec 10w40 and a k&n oil filter. but i just read in the manual that originally came with the car that you shouldnt use synthetic oil.

 

back then you shouldn't but running a blend is worse... if you want to use synthetic you should run mobile 1 .... but im cheap and i do my oil change every 2000 so I buy a nippon oil filter and castrol 20w-50... if you have money run nippon oil

 

iv never heard of nippon oil or filter whare do u get it?

 

so..... 20w-50 for maryland temp? or 10w-30.... or 10w-40? im lost

 

The factory service manual and owner's manual both quite clearly specify which oil weight to use for a given temperature. It's not rocket science.

Castrol GTX is well-known for being rotary engine friendly. As for synthetic or semi-synthetic engine oil, it is a waste of money unless the car spends time on the race track.

 

And you can't find it because the search engine is wack and words like oil, rx7, and 88 will yield no results. Go here to voice your outrage and maybe they'll fix this crap.

https://www.rx7club.com/showthread.php?t=680333
(yes I know he could have looked in the faq....shhhh)

No to the topic at hand.

In Florida its 20w50 year round, it gets too hot to be messin around w/ brown water. aka 10w-anything.

If you live somewhere that actually has a winter then thats the time for 10-30/40

And on a side note, you should all check out the FSM recommendations on coolant/H20 ratios those living in the south especially might be surprised.

 

I use royal purple. My car used to burn so much oil I tried everything and once I used royal purple I won't use anything else. Unless all my oil is burned off and none is available. Then I will use mobile 1 synthetic.