This oil does exactely what its supposed to do! Engine is quieter, runs smoother, and stays cooler. Unfortunately for me, my car calls for 5w30 and this is 5w40, thus my avg. mileage, after three tank refill periods, did go down by 1 mpg. (1995 Buick Roadmaster 350/Lt1 w/34000, yes only 34,000 miles). Combo city/hwy 15 mpg to 14 mpg. Oh yea, Walmart will probably be the best price around, however they sell it higher in the stores than online (and they will not honor/price match any online prices or ads, even if you choose the ads for that particular store). So, do their online ship to store option, you will have to pay online but at least you get the discounted price. Plus go to the Shell Rotella site and sometimes they offer a $5 mail in rebate offer to, makes it 14.22 a gallon, not bad!

And if you take advantage of the oils ability to take care of your engine for extended oil change periods, it is the most economical. Buy oil filters designed specifically for synthetic oil and extended oil change periods and you can safely change oil every 10,000 miles. If you install a bypass oil filter in addition to your regular spin on filter you can extend your oil change periods even further. On my truck and car I change the element in my bypass filter every 5000 miles. I change my spin on filter every 10,000 miles. I also send a small sample of my oil to an oil testing lab at regular intervals to determine if I need to change oil and to determine the health of my engine. I have purposely not endorsed any products other than this oil so you can do your own research.

A very good motor oil for my motorcycles. Inexpensive compared to other top end brands. Whenever I change my oil (about 3k to 5k miles), the old oil is very clean and I have never seen any metal particulates. Im sure other oils do the same job but the price sets Rotella apart.

[This review was collected as part of a promotion.] I do my own work on my diesel vehicles and only run diesel oil made for diesel engines. Shell / Rotella is a great fit for my vehicles and meets the specifications from the vehicle manufacture - Mercedes Benz. I will also investigate to see if this will work in my diesel tractor.

I had previously done an oil change with an ACDelco filter and Mobil-1 5W-30 and noticed my oil pressure slowly getting lower and lower over a period of a few weeks. Oil pressure went from around 28psi at idle to less than 19psi and wouldn’t go over 35psi when driving, I diagnosed it as a defective or collapsed filter and switched to a Wix XP filter and this Shell Rotella T6 5W-40 for some extra viscosity and protection at operating temp, since then my oil pressure has been great, 33psi at idle and oil pressure goes well over 45psi when accelerating. So if you’ve got a gen 3 or 4 Vortec with low oil pressure consider making the switch to Shell Rotella and either a Napa gold or Wix XP filter.

The oil is outstanding!! Your packaging is horrific!! Three separate 1 gal containers in a large box no packaging the box was torn open!! I am not sure what training you give your technician on boxing but they need to be retrained!! Again oil awesome but packaging is disappointing

Get the 5 W-40 vs. the 15W-40. Especially if you're living anywhere the temp goes below 40 degrees often. Check the forums and do the research. No comparison in performance! If you live in a hot climate, the 15W weight is fine. Happy motoring!!

Motorcycle is a Honda ST1300 with 13000 miles on it. Have used the Rotella Synthetic, ostensibly advertised for diesel engines, but without the "high efficiency" additives, it works very well with my motorcycle. Clutch is just as good as new, and the engine uses no oil. To boot, the container has four quarts in it, and that just fills the ST. The Amsoil salesman stated that there is now no zirconium in Rotella T synthetic, but in my opinion there is a limit to the addition of trace elements to motor oil, and since the synthetic is a superior lubricant that will not carmelize, it is plenty adequate for everything except maybe flat out racing.

The price went up from 3 months ago. That was not good!

Works great for my motorcycle!