Thanks Macca, i have been searching the net and cant seem to get a definite answer, so think i will go for the straight GL5 as you suggested to keep it safe.
Amsoil gets a good wrap on our forums. However, understandably, many people are put off by its high cost.
Interestingly, Amsoil suggest that their oil is cheaper over the long term because you only have to change Amsoil oil once every 25,000 miles! See here:
"While competing motor oils must be changed up to five times over 25,000 miles, AMSOIL Synthetic Motor Oil is only changed once, saving both time and money."
Amsoil's reasoning seems to be that other oil manufacturers recommend 5,000klm oil changes due to profit - it means more oil gets sold!
Personally, I'm nervous at the thought of leaving any brand or type of oil in my engine for 40,000klms, even if it's super dooper, platinum grade, amazing grade oil.
My intuition suggests that I'm better off doing more regular changes with "normal" synthetic oil, rather than extending the service intervals using top shelf oil ie. Change oil every 5k with Castrol / Shell / other reputable brand oil, rather than change oil once every 40K with Amsoil.
Having said that, I don't have the technical data or knowledge to verify or dispute Amsoil's claims.
My thoughts are, if amsoil claim their oil can handle 40,000kms, then it should have no trouble taking a good flogging for 10,000kms. Any other oil I wouldn't leave in my engine for much more then 5000kms.
Interesting seeing the oils they use for comparison. I use Castrol Edge in mine, but they compared Amsol to Castrol GTX which is the cheaper mineral stuff. They did have Mobil 1 Extended in there, so I guess they were going for a broad spectrum.
Amsoil looks to be good stuff, but if you were to try to use it for an extended period, then I'd suggest checking the oil regularly to see any change in colour. Start with a proper flush and see how long until it starts turning black.
Would be interested to see anyone elses view on this.
So i need some gearbox oil, been trying to find the 75w85 gl4 listed at the beginning of this thread but cant find any anywhere, have found some 75w80 and 75w90 in both motul and redline im interested in which are synthetic but it doesnt say whether they are gl4 on the description and the person i spoke to didnt know either so does anyone know will redline mt90 (75w90) or the motul equivalent be ok? At $150 for three litres i'd say so but just wanted to check.
Also the guy i spoke to said that in his big book of oils it had 75w90 listed for the gearbox in vr4s and evo's not 75w85
Redline mt90 is fine, it's what I have in the leggy at the moment. If you want it cheaper, try www.performancelub.com
I have used him reguarly over the last 5 years, and am always happy with his service.
Hey guys, Im no expert in oils, but this brand is well up there and has been mentioned on this tread. I believe this product should be better then the Mitsubishi Sold brand, however just thought it get everyones opinion on this particular oil before i go putting it in.
Attached is the fact sheet on the ELF "Elfmatic T4"
General rule of thumb, if it's SPIII, it'll be okay. That one doesn't say that it is SPIII but it does say it 'fulfills the OEM requirements of' Mitsubishi SPIII ATF, so I can't see why it wouldn't be alright. Having said that, I can't see any disadvantage in just using the proper recommended diaqueen SPIII.
In the case of the autos I think its less a case of better or worse and more a case of right and wrong, hopefully someone else can tell you 100% it'll be fine.