Sometimes I'm convinced on using it...then sometimes I'm convinced on not using it. I can't seem to make up my mind! Oh...and I'm new here to this forum, so excuse me if people have already had this discussion already. But I had some trouble finding discussions on this topic. Ok...enough talk... I have a '93 cavalier with about 40k on the transmission. So as you can see... I don't do heavy towing or drag racing, but I do a lot of stop-n-go driving (just to work) and live in a very hot climate (houston). I wanted to know if I'm wasting my money using synthetics on a car like mine. I most likely will not use it on my engine(it just isn't worth it), but it would not cost me an arm and a leg to use it on my transmission. Aside from that...I mainly want to use synthetics in hopes of extending the life of my tranmsission. I want to use the best fluids for my tranny and hopefully be able to see more then 100+ or 200+ miles. I've seen the reviews done at "bobistheoilguy" and saw the difference between dino oil and synthetics....and it seemed to me synthetics didn't really seem to do any good when you first accelerate the car. So I don't know what to think here. Does synthetic really work? and if I used synthetics would I prolong the life of my transmission if I used it? I think you get the idea of what I'm trying to accomplish. So any recommendation that you can provide would be of great great value to me. Thanks for any help you can give. -jer ps-in case your wondering. My engine has 160k and my transmission has 40k(re-built). I use valvoline (dino oil) for my engine and Castrol ATF for my Transmission.