Synthetic oils vs old school oil

[boxcorsair]

Hi all

This might be a bit of a non-issue, but I am of to grab various oils and lubes this weekend for engine, gearbox, trunnions etc. I have all the recommended types from the workshop manual, however the majority of local shops, a least, appear to be selling synthetic alternatives.

Is there any difference in operation? Is there any impact of the grade/type.. e.g. is EP90 the same regardless?

Cheers all

[Doug Paterson]

EP90 is definitely not the same regardless.

You don't want to put GL5 spec EP90 in our cars - only GL4

Although I understand that there are now some GL5 spec oils which are safe to use you must check they won't degrade the bronze phosphorous (?) metals in our diffs & boxes

GL5 is readily found - GL4 is not so easy.  Mail order / internet seems best source.

[willcolumbine]

You can get GL4 from Halfords. It is clearly marked on the front of the bottle and should do the trick for gearbox and diff. As for the engine, I have always used 20/50 from Duckhams, Millers or Halfords. I have heard it said that once run in a Spit can use a synthetic like Mobil1 but it's not something I've tried!

[Doug Paterson]

You can get GL4 EP80/90 at Halfords - which is good enough really.

I've never seen GL4 EP90 in there tho - keep looking hopefully mind.....

I'm using Valvoline Racing VR1 20W50 in the engine.  Great Stuff.

[boxcorsair]

Thanks all. I'll have a look in Halfords tomorrow - got to pick up some other bits ad bobs. Found this place on line... seems ok. £16 for 5L. http://www.supplyshed.biz/gearoils.html

[Doug Paterson]

boxcorsair wrote:

Thanks all. I'll have a look in Halfords tomorrow - got to pick up some other bits ad bobs. Found this place on line... seems ok. £16 for 5L. http://www.supplyshed.biz/gearoils.html

Good find.  That's a good price for GL4 EP90.  Never heard of the brand but will give it a look.

[Fizzy]

yesterday i picked up some comma GL4 ep80 fom my local wilkinson's of all places. was about 2-3 quid for a litre.

[rotoflex]

I tried Mobil1 synthetic oil in my GT6 and it found its way out through places regular oil never had before!  So I switched back.

This was back when Mobil1 first came out, though, it may have changed.

[drofgum]

I have had similar experiences to Rotoflex's using Amsoil products in both the engine and the gearbox. I stopped using them and the leakage abated. The car still marks its territory, but nowhere near as much or as expensively. YMMV.
                                                                    Cheers,
                                                                    Paul