Royal Purple (36140-6PK HPS 10W-40 Synthetic Motor Oil with Synerlec Additive Technology - 1 Quart, (Case of 6)

I use it in my 1973 Ford f250 360CI. Runs noticeably quieter and very smooth compared to your average conventional oil. I would say this is great stuff for older engines with flat-tappets. I messaged Royal Purple and asked what they recommended for an older car and this is the stuff. Lots of Zinc and Phosphorous/ZDDP substitute for the older technology. It also has an extremely high viscosity index, out of any oil I've seen, so you know it will perform great in those temp extremes as well, hot and cold. At about 11 bucks a quart if you buy in bulk, it's also hard to beat the price when comparing to Amsoil or Redline, although those would be great choices as well.Comparing other options, Amsoil is a bit thinner than this and offers a little bit better cold weather performance and longevity, but is pretty expensive. Redline is nice because you know what they put in it, no secrets with them--very high quality group 5 ingredients. It's also the most robust, and probably offers the greatest protection in extreme operation. Don't necessarily know what they put in the HPS, though I imagine it's a high quality group 4/5 ester/PAO base, either that or its got a pretty beastly additive package to perform the way it does. Mobil is another obvious option and is probably the best all-rounder for your newer cars, though some of these "boutique" oils I've mentioned offer more specific things if you need them.Overall, I think this one wins the comparison for price and if you don't change the oil every 20,000 miles. Personally, I wouldn't wait that long on any vehicle. Maybe 10,000 at the most in an engine that is perfectly sound.

If you are familiar with automobiles and engines you will know that the rotary engine can be a weird animal. The oil system is extremely important due to the fact that it is getting injected into the "cylinders" or rotors when the engine is running regularly. I was very hesitant about putting an all synthetic oil into my engine because of mixed ideas about oil with the Renesis engine. Not to mention the owner's manual says its a bad idea but every specialized oil for rotaries from Japan is synthetic. I have over 144K on my engine and want to extend the life of the engine before I have to rebuild the apex and side housing seals. I had some worries about synthetic oils because of deposits which can kill a rotary engine. I wanted to make sure whatever I was putting in would burn off clean and keep my apex seals, the life of the engine, in tact.I have used one full 12 quart box of this oil and what I have to say about the product when it comes to rotaries is that it seems to do very well. I haven't had to use as much oil as when I was using Pennzoil standard oil. Usually when using my old brand I had to be psycho about monitoring the oil level. This stuff seems to go a bit further and the burn off doesn't have much smell at all. When you hit 9RPMS with the Renesis engine you can typically smell an oil burn off which is still present with this but not as severe. The engine sounds like its running quieter but that could just be my imagination.I have to give props to the Royal Purple team that included information on their website about Rotary engines and their relation to Royal Purple they are what sold me on it.I will continue using this product even if it is more expensive. I love my car and keeping its heart(engine) alive is a very big deal to me. If you're wondering, the product really is purple.

I bought this oil for my 2000 Dodge Durango 4.7L V8 SLT 4x4 which has around 150k miles on it. I feel I got a very good price on this oil and it's very long lasting. You can go many more miles on this synthetic oil VS. regular oil. This oil is also supposed to add a little horsepower, torque and fuel mileage to the engine VS. regular oil because it provides lesser friction inside the engine. I only put around 5k miles on my Durango a year and this oil lasts the entire 5k miles, no problem.

great as always, continue to buy

Absolutely love royal purple oil. Top quality! The shipping was super fast and packaging was first rate well done gentleman.

High performance oil used in a Mustang, great protection for your engine. Change oil at 1 year or 7500 miles for my application, no worries

Royal Purple 36530 HPS Product is more money, But noticibly better Performance & Gas Mileage over the standard Royal Purple High Performance Synthetic Motor Oil. The Patented Synerlec & Zinc additives make a big difference that are missing from the cheaper Royal Purple oil!

good oil engine is okay… sounds lil different. But feel like its a downgrade from the RP 5w40My advice its same price buy the 5w40 it’s supposed to be for high performance vehicles and i use it my sports car (I rebuilt my car engine and will be using RP XPR 5w30). And my vehicle was running a lot better on it.Overall its good oil but I promise ya the 5w40 is way better