Royal PurpleHPS Street Synthetic Motor Oil 20W-50 1 qt (Case of 12)

Have been using this for 5+ years and no issues, no leaking seals, no noisy lifters, etc. Had the valve covers off a couple years ago and all looked good there too--no gunk and funk in the corners. Sent a sample of used oil to blackstone and zinc was ~1200 (right where it should be for my car). I hate the price and know there's a huge markup (you can tell when stores are clearing isles and it's $2.50 a quart). But, even thru Amazon, the price is cheaper than my local auto parts store.

I've use Royal Purple for years in my motorcycles. The 20W-50 HPS works great, this oil can only be used in non-catalytic converter motors because of the high concentration of zinc and phosphorus which are anti wear additives, they are the sacrificial material between metal parts. If used in a catalytic vehicle it tends to foul the converter.

Exceptional performance in my 117 cu in S&S motor.

I have been using Royal Purple ever since i heard about it in the 90's working at an oil distribution company. It is a remarkable product that when shopped for can be found at a reasonable price. The benefits are outstanding. Better fuel economy, better quality, longer between oil changes, just all around great product. This purchase is for my Exmark lawn mower. I change the oul once a year and could not be happier with what it does to protect my equipment. My old mower i had for 12 years with no mechanical issues and engine ran and performed as new. Only reason i got new mower was in fear of nonengine issues arising. So while i could resale it and purchase this upgraded one was a no brainer. This was more oil that i was planning to buy but this was the best price per quart available. So i will have oil availble for a few years. Do not hesitate to buy Royal Purple you will not be disappointed and happy with the benefits it provides.