I've always been curious about this brand, so I finally put in their Gear 300 in my tranny and 8100 Eco-nergy 5W30 in my engine. Previously I used Mobil 1 and Redline MT90.

On the tranny side, the shifting feels heavier, not clunckly though. Now there is less noise when I shift and overall it does feel smother. Two things that sold me on their Gear 300 is their claim that their oil is unshearable, and the fact that it's an Ester based synthetic, which is supposed the holy grail of synthetics.

On the engine side, Motul is also better than Mobil 1. Yes it did feel smoother, but one thing that stood out was that when I lifted off the throttle completely the car didn't surge forward as much as it used to with the Mobil 1 in it. That can only be caused by one thing, less friction in the engine. It also did quiet down the engine a little bit. Next up I'm gonna try their 300V oil, which is Ester based too.

One thing that I always found strange about the Mobil 1 was that it was always very hard to check the oil level, because it would shear away from the dip stick every time I checked it. I don't know if that was normal or not, but I don't have that problem with the Motul. And this also worried me: http://www.3si.org/forum/showthread.php?t=370220

Where did you get your Motul engine oil?

There's an Autobacs store 30 min from my house. Don't know if they have them in IL. $14 per liter for the Gear 300 and $8 per liter for the 8100. You can also try motorspot.com. I've never ordered from them, but they do have a lot of info about Motul.

is the 8100 100% synthetic?

M1 is noisy and a Group III oil.
I just changed to Royal Purple - love it.
Use Motul in my bikes. Killer lube.

is the 8100 100% synthetic?

Yes, but it's not ester based. It's a group iv or PAO oil. It's still a true synthetic though. All group IV PAO or group V Ester based oils are true synthetics. Group III oils are basically super refined petroleum. I know Castrol Syntec is a group III oil. In europe Castrol Syntec goes by another name. European companies can't label group III oils as synthetic.

is the 8100 100% synthetic?

Yes, but it's not ester based. It's a group iv or PAO oil. It's still a true synthetic though. All group IV PAO or group V Ester based oils are true synthetics. Group III oils are basically super refined petroleum. I know Castrol Syntec is a group III oil. In europe Castrol Syntec goes by another name. European companies can't label group III oils as synthetic.

Euro-Castrol is known as "GC"
It originally was green in color, now, it's gold, hence still being called "GC"
It's an 0w30 oil and hard to find here.