Engine oil Kendall or MOTUL

I replaced the company oil to motul 10w40 engine oil, the changes weren't drastic but the milage and smoothness improved over the time

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.

I used kendall 20w50 in race engines, though those saw 7-8 grand shifts, and lasted about a year.

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.

MOTUL 8100 ECO-LITE 5W-30: Don't let the name fool you, it's not actually that great for fuel economy compared to some others with a lower KV. With a TBN of 8.5, VI of 166 and KV of 11.4, this is one of the best 5W-30 oils you can get. This is leaning more towards a higher performance oil rather than focusing on fuel econ. The high TBN means you can get away with longer OCIs as well. I am personally using this in our 1.8L Corolla at home and the car runs smoothly and quietly and still gives us a good fuel average (for our use case), so I can't complain.

Motul 5w-40 in my ej255 pretty much since the whole life of the engine since its engine 35k ago. ... went back to Motul right after.

I'm one of the Motul 5w40 users. I use it because I live in west Texas where we will have weeks in a row over 100⁰F. I've also modified my car and take it to track days. This was the oil recommended by my tuner so that's what I use.

I have been running Motul 5w30 Xclean EFE and have used Pennzoil Ultra Platinum as well.

This sub loves to praise motul, but it caused me to foul up my spark plugs and have misfires. I tried both the 5W30 like the manual calls for and 5W40, but shortly after I changed to motul my plugs fouled up. I replaced them, they fouled up and misfired again. I tried it a third time cleaning the MAF sensor, checking if the plugs were torqued okay, checking the seal on the coil packs, etc... still fouled up. I finally guessed it was the motul and did an oil change away from motul and swapped the plugs again. 14k later no fouling.