Hi,

 

Hello to all.  I'm new to the forum and as always with a newbie I've got a question.

 

I've been on to Skoda and searched through the forum but I can't seem to find out whether the gearbox oil should be mineral or semi synthetic 75w-90 GL4?  I wondered if anybody could help? 

This subject had always a ton of myths and gossips attached. In fact things are very clear for those willing to read and capable to understand basic scientific facts. You can find a detailed answer in here:
 
The Engine Oil Bible

 

PS: What stands GLi for in your car's description?

Hi, I've got a 99 1.6 mpi Felly & IIRC have used EP 75W/80 GL-4 (Halfords). 

PS: What stands GLi for in your car's description?

 

Grand Lux Injection, I think?

 

Still non the wiser.  Different companies recommend different oils.  Some mineral and others semi-synthetic.  The Halfords stuff is mineral, Comma recommend SX75w-90 which is semi-synthetic.  So, I'm guessing it can't make a lot of difference.

Fairly sure it won't make any difference to an old diesel engine.

^ Well I'm still ok at 115k so can't be going too far wrong! 

Thanks for the replies.  I had a look in Halfords when I was in there the other day.  The car took semi-synthetic and the commercial 1.9D took mineral.  I'm assuming they are the same box so why the different oils?  If they can't make up their minds like you said can't make much difference.