As I intend to change the various oils on my car in the next few weeks, I did a bit of research on the topic and also contacted
Opie Oils for a recommendation on which oil to use.
As this may be of interest to others as well (and as I've seen quite a few threads with the topic), I'd like to share my research results with you on which oil is best as (i) engine oil, (ii) gear oil and (iii) differential oil if using a Quaife differential.
1) Engine oil
Fuchs Titan Race Pro S 5W40 see here for the link on the Opie Oil website - it was also called Silkolene Pro Race before. E92Fan also recommended this as the best oil currently available.
Cost: currently 9.80 GBP per litre, 41.50 for 5 liters.
For a 335i you would need 6.5 liters, except if you have (like me) additional oil coolers. Personally, I need around 7.5 - 8 liters, having the AR Design oil cooler (in front of the radiator) and a much bigger oil cooler as replacement for the stock core.
2) Gear oil
Fuchs Titan Sintofluid SAE 75W80 see here for the link on the Opie oil website - fully synthetic, to use for cars with
manual transmissions.
Cost: currently 9.25 GBP per litre.
For a 335i you would need 2 liters. Even though BMW says that the gear oil does not need to be changed (fill for life fluid), I believe it still to be a good idea to change it after some time.
3) Differential oil
Fuchs Titan Race SYN 5 75W90 see here for the link on the Opie oil website - a fully synthetic high performance gear oil, also know previously as Silkolene SYN 5 75w-90. Pursuant to Opie oils the only approved oil for Quaife differentials, although
Birds who installed my Quaife diff said that they always use Mobil 1 VS 600 (which however does not seem to be available).
Cost: currently 10.62 GBP per litre.
For a 335i you would need 1.5 litres (i.e. you would have to order 2 liters). As I will have the
finned differential cover from VAC Motorsports installed on my car shortly (which doubles the oil capacity) I needed 3 litres.
4) Oil Filter
As you may want to order an oil filter at the same time, the one needed for our cars is the
UFI hydraulic oil filter element in pleated paper 25.058.00 see here for the link on the Opie oil website.
Cost: currently 11.86 GBP (you can get 2 for 21.34 GBP)
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For those living outside of the UK it may be interesting to know that Opie also delivers outside of the UK. Shipping costs in my case were around 21 GBP which I found ok as the prices were otherwise very competitive.
Alpina_B3_Lux