i mean i know lots of you are going to say diff things but i was curious because i heard lots of good things from redline and i was planning on chaning my tan oil to test out something because some times it feels weird going into second gear.. guessing its the sycros but if anyone else has any good ones please let me know

 

I think pretty much all the synthetic stuff is praised: Redline, Amsoil, Royal Purple, Neo, Mobil 1.

 

So far I've only tried Mobil 1 and Royal Purple. Shitfting felt much smoother with Royal Purple, especially when cold. YMMV.

 

Redline and neo are my favs

 

I've tried Redline, Amsoil, Neo, and Royal Purple (current oil) in some way or another in my FC and FD. They're all great and a step up from non synthetics.

 

They're all very good. I'm using Neo 75w-90HD and it's an excellent oil for the $$. I've also had good success with the Redline MT series.

Bottom line, all the oils mentioned so far are top notch synthetics. They will all perform better than a basic petrol gear oil. They will cure some shifting problems, but not all.

Dave

 

If you do a search, you will find a thread about Neo. It sonuds like Neo may be the best product out there. I will be using it when I decide to change out my Redline.

 

I remember Peter Farrell stating synthetic oils ruin the gearboxes in RX-7's. Peter said he found that out through all the servicing of RX-7's over the years and also in his race cars. The problems stopped he said when he went back to non sythetic after the gearboxes were replaced.

He drove a buddies car which the gearbox was working and looked at him and said "You're running synthetic gear oil aren't you?" My buddy was...

 

I believe that had to do with the early synthetic gear oils not having proper friction modifiers. They have come a long way over the last 4-5 years.

Just about all the track guys I've been around swear by the current crop of synthetic oils as they will also lower the temps of the gear box during hard running (thus helping the life of it).

 

Redline MT90 believer here.

 

SWEPCO
Porsche Club favorite

 

N E O

 

SWEPCO also. Based on input from long time rotary mechanic in Az.

 

Using what works in another type of gearbox is flawed logic. The synchros are the primary issue when you change oils, and using different varieties of oil will affect how well the synchros grip the gear as you engage each shift. Every kind of gearbox is different in its synchro behavior, and even every gearbox is a little unique.

One issue with early and/or cheap GL-5 oils is the kind of EP additives - reactive sulfur and phosphorus compounds make for a cheap, effective GL-5 EP package. But they eat most synchros or at least speed their wear. Also, the extra lubricity of a synthetic means it's harder for the synchro to grip the gear and synchronize - in some cases this leads to damage on the synchro teeth and dog teeth of the gear. Especially with worn synchros. Perhaps PFS was noticing these kinds of problems.

Newer and better GL-5s have EP additive packages that are largely absent of the nasty kinds of sulfur and phosphorus and do much less to the synchros. Redline, Amsoil, and Royal Purple are clearly in that category, and I believe Neo is too but they still haven't sent along the test data to prove it. (They have an outstanding promise to me).

Dave

 

ive tried redline and neo .. think im switching back to redline

 

This a perfect thread for me because I am going to change mine this weekend and was wondering what type of oil I was going to use. Your imput on this topicis very helpful!!

thanks,
-josh

 

I use Royal Purple in the tranny and diff (as well as in my M3).

The main reason I picked Royal Purple is that it's available from my local NAPA. I don't believe there is going to be a noticeable difference, of the same weights, between all the "upper" brand name synthetics.

Most people say "Hey, I just put Redline in and it's the best! I'll use it forever". Putting new fluid in of any kind is going to be better than even the best fluid that has 50k miles on it.

 

^ Bingo. That's what I was trying to say earlier.

 

I've used both Redline and Amsoil. Both were an improvement, especially in cold weather, but i tend to like the Amsoil. As far as i know they're all good products...my choice was simply based on personal preference of which one just 'felt better' to me. But any name brand synthetic will probably do you right.

 

I use royal purple and cold shifting is a lot better, but i hear good things about neo as well.

 

haha...thats the exact same reason why im using royal purple...napa is only down the street ^_^

 

Royal Purple here, love it

 

Not sure. I remember Peter said the gear boxes become sloppy and basically wear out. He said you can't fix them you throw them out as they are worn slam out.

 

That comment suggests that an oil with too much lubricity is preventing the synchros from gripping the gears, so that the gear isn't synchronized when the clutch sleeve teeth hit the gear dog teeth. This is much worse than synchro wear since the drive gears and clutch sleeves are taking the abuse, and they cost $200/ea. Considering there are 3 sleeves and 5 gears that would wear out, that's definitely reason to pitch the thing.

Dave

 

Sounds like synthetic oils without the proper friction modifiers. It wasn't too long ago you had to do both, add a friction modifier AND the synthetic oil.