MT oil & GEAR oil.
 

What is the best and where is the cheapest place to get it? Thanks in advance.

Brady

i like red line synthetic. cheapest shop around DSL baby!

What is DSL? Do they have web site?

I don't recommend Redline in Mazda transmissions. I use it religiously in my Honda and used it in my FD for a while. While it cuts down on the cold notchiness - I don't think it offers enough friction to the synchros when warmed up.

Well what is your favorite?

clayne were you using the mtl fluid?

No. MT-90.

Brady, right now I'm using some Valvoline gear oil I got from a mechanic friend. Works fine.

And that stuff is like free compared to the price of Redline. :)
I wonder how the Mobil 1 synthetic works? Seen it a autozone.

ok they have mtl that i use and like

Best is subjective. Some use regular MT/diff. oil, most use synthetics. Of the latter, there's several to choose from, Redline, Amsoil, Royal Purple, Mobil1, etc. Mobil1 is the cheapest and easiest to find.

mad_7: I have used both MTL and MT-90. Both had the same thing: Reduced cold notchiness BUT increased frequency of grinds when shifting fast. There's something about Redline that doesn't typically go well with the synchros in Mazda trans over the long-term.

The Vavoline gear/trans oil is simple and effective.

Like I said, I still use Redline in my Civic.

I love MT-90 great stuff

MTL is too thin. At least use MT-90 if you want to stay with Redline.

So I should be OK if I go ahead and use Mobil 1 from auto zone? :)

Redline 20w50 for engine and MT-90 for tranny.

DIff gets 75w90 or shock proof 250w

What Clayne was saying is that the synthetic gear lube (like MT-90, amsoil, others) provides too little friction for the syncros. They need some level of friction to operate properly. You will have the same issue with most of the 75-90w (GL-5)full synthetic gear lubes. Some people have experienced syncro problems with the GL-5 full synthetic gear lubes and some have not. IMO your better off running something not quite as slippery and changing it once a year. A GL-4 lube would be better suited for the mt application. I run amsoil 75-90w and have had no issues. I'm also fairly stock, reliability mods only. :)

My poor car is a long long way from stock. :)

Actually the Redline has a gear lub that addresses the friction for the synchros.

As a matter of fact, they do sucj a good job at it that it shifts so smooth........