1991 n/a fc, currently IM useing 15-40 for motor oil and going to be swapping out the trans tomorrow. What oils should I be using for both engine and trans?

 

Engine: 20W-50. Manual transmission: 75W-90

 

Awesome. Thanks.

 

Engine 10w 40 tranny 75w 90

 

+1

 

The recommended oil viscosity is listed in the factory service manual, which you can download for free if you go to the links in the FAQ for this section. I recommend synthetic oil for the manual transmission (any brand except Mobil One). Conventional oil is fine for the transmission if you are on a budget or if you don't have time to shop for synthetic, but the shifting will feel notchy.

If I were driving on the streets of LA, I would use Castrol GTX 10W40 or 20W50 in the engine, and Red Line MT-90 in the manual transmission.

 

+1 My is a summer only driver on the "North Coast" and that is what I use as well.

 

Would synthetic oils actually be okay on a car that is 20years old? Why the 20w50 for la driving? Is it the weather conditions? Or just the consistent stop and go traffic?

 

Oil weight is based on ambient temperature and use - check the manual or the sticker under the hood. In LA using 10w-40 maybe okay for a n/a engine, but 20w-50 is cheap insurance, for a T2 use 20W-50. I would just stick with the Castrol GTX for use on the street. If this was a race engine in a track car, then maybe a very good low ash synthetic would be advisable.

 

Sorry ment to say I was using 10w-40 for the engine, but okay. so far I am okay with the engine for LA driving. gona pick some trans oil in the weeks to come so I can finish it up. Thanks for the info.