Went in for a transmission fluid exchange last week, and the dealer used BG 3144 Fluid instead of Matic S in my 2007 G35x.

They have offered to change the fluid out for Matic S. Do you think there is any damage done in a week? The transmission is behaving better than it did before the fluid change, I just want to get an opinion if I should have it changed to Matic S or not. Thanks in advance.

 

You should probably just get it changed to the correct fluid.
It is most likely behaving better now just because it's fresh fluid. Not sure on the differences between the two though.

 

So I went ahead and had them exchange the fluid for Matic S.

I do not recommend the BG 3144 fluid, it made shifts much smoother which in my opinion is undesirable.

The gear shifts with the Matis S are crisper. Just a note to G owners in Edmonton, Alberta, most dealerships here use alternate fluids and you will need to explicitly state that you want Matic S.

 

Thanks for the info, I have an 07 G35x as well (82000km on it) and feel like my tranny is not consistent in how it behaves. It sometimes bogs or sandbags off idle on throttle tip in, and when accelerating away at fairly light throttle it goes through all the gears quickly but instead of a forward surge which I think is common for most auto trannies, it feels like a loss of power during each shift. Would this be considered normal or is it time for a fluid change?