Hello Rennlist, hope you're all having a nice hermetically sealed Saturday.

I've done some searching and I've seen several options for manual transmission gear oil mentioned around here. I hope this doesn't start a holy war, but I'm interested in opinions on the relative benefits of different types. In particular:

1. Mobil Delvac
2. Mobil 1 PTX
3. Motul Gear 300
4. Liqui Moly GL5

...all presumably in 75w90. Does anybody have experience with more than one of these and can offer a comparison? Are there different applications (weather, track vs. street, etc.) that favor one over the others? My vehicle is a 2012 C4S Cab. Most of the conversations around here seem to have been driven by supply availability, but luckily I have easy sources for all 4. Any opinions or thoughts are appreciated.

 

Motionless 300 is good. I tried it and it was much better than the Delvac the dealer had installed. However, the PTX is even better. It’s worth the additional cost.

 

I hate spellcheck. I meant to write Motul 300.

 

PTX is worth the hassle to find and the cost to pay.

 

2009 C2S 153K miles MT

What does it say to use in your manual?

Peace
Bruce in Philly

 

Nice to get an unequivocal response like that. Ordering 4L of PTX now. Thanks everybody!

 

What no Shell OEM approved ...Spirax S5 ATE

 

3 Liters of PTX is sufficient unless some is spilled. I have found that Sunset Porsche typically has the best prices and service.

 

Yeah I got 4 just sort of for contingency. If it was at the O'Reilly down the street I'd just get three...but I'd hate to mess up and be short when it's a week or more to get another liter. If I end up using 2.6-2.8 as expected, well then I'll only need 2 more next time.

 

You might have to call it since the p/n nor the website lists it.

MobiLube PTX 75W
90 000-043-204-20-SP
3x $90.33

 

I had the gear oil changed at my 8 year service interval even though it was not required. I read that it could improve the shift to 1st gear when the engine is cold.

The shop used Mobil Delvac. It made no noticable difference, so I called them after driving the car less than 100 miles on the Delvac. They offered to replace the Mobil with Motul. Change was made. Again, no noticable difference in the rough shift into first on a cold engine.

I've heard the PTX is good, but I'll wait until the change is required.

 

There are only really two options for manual street use , especially in slightly colder climates OEM approved Shell Spirax S5 ATE & Mobil PTX to minimize 1st to 2nd notchyness ... I went with Spirax ATE due to availability and it has drastically reduced hard shifting especially when from cold. The only other one I considered which from a property perspective was very close to OEM was Swepco https://www.swepcolube.com/products/...etic-gear-lube ... For race applications others have said Motul , Redline work well due to higher temps but not as well in general street use where higher "race" temps are not achieved.

 

2009 C2S 153K miles

Check your owner's manual. It will denote the specifications and brand of oil to use. My manual denotes Mobilube PTX GL4.5. Delvac is not it. It is not to spec. It is not a GL 4.5. Dealers fill with the wrong stuff. I am always fascinated why folks don't read their manuals.... or dealers.

https://rennlist.com/forums/997-foru...-gear-oil.html

Peace
Bruce in Philly

 

My car suffers from a tight 1st gear when cold. It’s only when the car is rolling. If it’s a complete stop, goes right in. Anyway, I replaced with Mobil 1 PTX and made no difference. My car is a 99 996.

 

1st gear is designed to lock out when rolling. Your car is working as designed.

Peace
Bruce in Philly