Started using Shell 5w40 T-6 in my Cummins 2 years year round. Very happy with it. Even in -30 C the engine starts fairly easy and the gauge shows oil pressure right away. Also use the Shell 15w40 in my motorcycles with the wet clutch . This oil has the JASO MA rating for wet clutch applications to prevent the clutch from slipping. Oil with the JASO-MA does not have the additive which makes the oil extra slippery for engine oil applications. I have also used the 15w40 in my vehicle engines in the summer. Very happy with the result.

Great product for cheap. I run it in a 2001 twin turbo Audi V6 - 170K miles change at 10K miles, 2002 Nissan Pathfinder - 180K miles - changed at 5K miles, BMW R1200GSA motorcycle - 133K miles - changed at 4K miles. This oils exceeds all manufacturer's specifications, never had any issues. Last time I opened the valve covers on the bike it looked brand new in there at over 100K miles

My '99 Honda Valkyrie motorcycle, '02 BMW 1150GS motorbike, '91 Lexus LS400 and '04 Dodge 3500 diesel, all use Rotella synthetic. It is so nice to keep one oil for everything and still find that excellent cold weather starting and hot summer oil pressures are still great. I recommend this product without reservation.

Anyone with a Ford 6.0 PowerStroke who lives in a climate where it gets below freezing knows the engine makes knocking noises and is loud & unresponsive when the engine is started in cold weather if the block heater has not been plugged in. With synthetic Rotella T6, though, the engine is much quieter, and does not require as much warm-up time as compared to using conventional oil. Even if one uses a block heater at home, most people don't have that luxury to keep their truck plugged in while at work. It sure makes the drive home quieter and faster, not having to let the engine warm up as much before hitting the road

I live in South Florida. I had a timing chain rattle on my Mercedes diesel OM642 on cold startup with the recommended 0W-40 Mobile 1. Mobile 1 did not have 5W-40 for Mercedes diesel so I decided to go with this oil. My rattle is completely gone. The only downfall is I have to change it at 5k vs 10k. I am okay with that since the motor seems to be running smoother.

I've been using shell rotella t6 5w40 for about a year now and this oil is awesome! Run it in my 1994 jeep grand Cherokee 4.0l and my 1991 Volvo 740 turbo and the engines love it they run alot smoother and quieter and shell rotella t6 5w40 is my first choice for my vehicles for the protection of the internal parts of my engines and to keep them running strong and running long!

Have been running T-6 5W40 since 2011. Never had an issue getting the oil. Now I have had my first oil change in my 6.7 PSD and had to use Mobil Diesel oil. 5,000 miles in and can hear a difference in the sound of the engine. So, shell when I get my oil sample back will you still honor your engine warrant since I was not able to get your oil ? Yes seriously I miss your oil and hurry the heck up and get t-6 to us!!

After reading the reviews on this, I tried this in a 2001 YZ250 and a 2004 TTR225, both shifted hard after using it. I tried changing it again in the YZ250 and it didn't improve. I then returned to the previous brand, Valvoline 4 cycle Motorcycle oil and the shifting problem went away. Now the bikes easily slide into gear.

I use it in a 2007 Honda Rancher ES and it always starts right up like a champ. No slippage nothing I can't complain. I drive this bike hard and change the oil once per year or longer. Checked it the other day after like 13 months still looks ok could use a change so I'm going to do it. I'll probably use Rotella T6 again. It seems to be good stuff.

I use this oil in my car's GDI engine and I know several people who love using it in their high performance Subaru engines like that of the STi, WRX, and Forester XT. It just doesn't shear like other 5W-30 oils often do. I am very happy that Shell offers this product but it is very difficult to find in stores and usually online retailers offer it at a more premium price. I hope it is made more commonly available in the future!