Engine oil Castrol or MOTUL

I’ve used Castrol and Castrol High Mileage on my Mk6. At just over 143K miles, I’ve had no engine issues at all.

Been running Castrol in my VWs for 20 years. Never had any issues.

Castrol euro has been good to me for the last 120k miles.

I've recently started using Motul 7100 10w40. Actually I'm due for my first change and should get under it today. It's the only pull I've ever used that actually made a noticable difference in operation. The esters bond and quiet the motor to a noticable audible level. It's designed for motorcycles though and with the unique properties of this ester based oil, I'm taking a chance with carbon build up, but the protection at higher rpms it provides gives me confidence under those conditions, which is where carbon is best loosened at too. Supposedly this burns fairly clean for a synthetic, but IDK. I'm changing at 3k miles to see how it looks. May or may not extend it out, but has felt great so far in this 135k mile motor.

em troca do óleo eu sempre usei 5w30 da Castrol, ate agora com 227.000kms com o mesmo motor só misturei 2 oub3 vezes no deposito da gasolina. Sempre foi o meu carro e nunca me deixou na estrada

I'm using motul x clean 5w40 for the last 15 years on my m54b22 and it s perfect. I tried also ravenol, liquimolly but motul was the best.

I'm on my first run of Motul 7100. It's ester based and has truly made a noticable difference in operation. It's made for motorcycles and their higher revs in mind, with the esters actually bonding to metal- not just a strong film. The drawback here is that from this bonding, the oil can be a bit stronger to burn off, but I didn't feel, like mentioned in another comment, that the internal temps on an RE can't burn that off. Just need to be sure to drive it like it's supposed to be, with high rpms. Instantly on first change I could notice quieter and smoother operation. I'm really not concerned about it not burning high enough, but as always, the most important thing is staying on top of oil changes routinely and timely. That is what truly kills most of these motors. In fact, I can't say I've really ever heard anyone lose a motor and say it was because "this" oil was used.. Unless it was something or some grade that shouldn't have been used at all in the first place.

I'm seeing a lot of strife around these comment parts on this post; but I will tell you this: If previous owner used only conventional, you best use conventional for the sake of the rubber seals on the block. If you want to eventually run synthetic after your first rebuild, be my guest, although I would recommend going the sohn adapter at that point, just for extra insurance that what you're doing is good for the engine.

I don't know where you're located, but I've personally ran Castrol GTX oil in all my cars up until now; the only thing is, it's harder and harder to find conventional oil that is of thinner grades. Which isn't a bad thing, because the RX8 needs thicker oil than what's on the oil cap anyway! 5w-30 should be your minimum thickness, but really, it's recommended you go thicker, to like 10w-40 for year-round, and 20w-50 for track days or extremely hot climates. There's this shell oil for diesel that's rated at 15w-40 that I was going to potentially pick up and start using. Yeah your fuel economy is gonna drop a tad, but you're really doing it for the sake of your bearings.

P.S. get an oil catch can that vents to atmosphere if legal in your area. It will save you heaps of headaches down the road ????

I run 10w40 5100 motul now. on all bikes etc.

Clutch doesn't like the full syn stuff.

cu cat l am folosit mai mult am ajuns la concluzia ca castrol e un gunoi, cel putin pt motorul meu si am trecut la uleiul original ca sa nu le mai incerc pe toate