Thread: synthetic vs mineral in the auto

Originally Posted by mcrover

And yes with snappier shifts it will wear your sprags and gear train faster.

Now as far as Castrol is concerned, unless your worried about extended service periods then stick with mineral while you can.

There is very little advantages in going to full synth unless your wallet is too heavy, semi's are a different story and a little more affordable.

They do state that some of the synth oils will take higher temps but this is the base oil they are talking about, the addatives (e.g. anti foaming agents, surfactants, detergents) will all still burn out at the same temps as it would with mineral.

The main reason for changing your trans juice is because of contamination.

Clutch material(mainly), chrome off bearings and sprags, metal off the gear train and water and mud/dirt if there has been a breach.

Standard Dextron 3 ATF is good for about 20,000kms under normal use and if your doing lots of towing then look at a more efficient trans oil cooler as when that light comes on, your oil is stuffed regardless of what you use.

Before I get flamed about this, I use Castrol oil analysis at $40 per test......do you......

The D1 trans pan drop is 4.5ltrs and from dry is 11ltrs including converter.

If changing your fluid, go and get a $45 filter as well and remove the pan and change the filter which is simple to do, and if your careful you wont even need to change the trans pan gasket.

It isnt much use changing the fluid without the filter as your then just dragging cleanish oil through a dirty filter which will work against having any improovement.

In short, full synth isnt really worth it, semi might be worth it if youve got a high stall, modded valve body or cluth packs or towing alot but in most applications your mineral Dex 3 is plenty good enough.

I will rephrase though, with the said mods I would be using semi synth.

To answer one of the other questions, there are heaps of oil coolers on the market that are better than the Rover unit (which is pretty damn good by all accounts) but you need to go to a supplier such as a radiator joint or transmission joint rather than repco or Bursons and deffinatly not Supercheap.

Originally Posted by mcrover

What temp does the light come on Edddo?

Ive had mine pretty damn hot, didnt have a thermo gun to test the temp but I couldnt touch the pan and the light wasnt coming on and yes it does work and is wired up.

The Auto Temp. light is off at Temps below 123C/253F and on at Temps above 130C/266F