Royal Purple 11748 HMX SAE 5W-30 High-Mileage Synthetic Motor Oil - 5 Quart

My 2010 GMC Sierra runs noticeably better on the highway. Would recommend!

I've been using this oil for my past 3-4 oil changes. I changed to this oil from Castrol magnitic 5w-30. I have to say that my oil consumption way less than with Castrol. In between oil changes, every 3000 miles, I go through a quart. Motor is at 184,000 miles.After the first time using this oil, my oil was very dark. Stayed that way for 2-3 oil changes. On my 4th oil change, I noticed I could still see a faint tinge of purple in the oil. That attests to the cleaning that the oil does, at least for me.This oil paired with a wix XP oil filter work really well for my SBC.

I'm driving a vehicle that has 250k miles on it and had probably never had any kind of engine treatment, so of corse the top of the head had allot of carbon build up... I've heard only good things about Royal Purple oil and filter, so I did some more research and found I don't have to add any kinda of engine treatment that could possibly cause damage to seals or gaskets... I wanted a product to basically pour in run for a period of time that's not an additive... I have now had Royal Purple high millage oil and filter in it for about 450 miles.. Im highly impressed with the power gain (whitch isn't much), the idle is cleaner aswell as inside my valvue cover looks clean enough to eat off of. I'm going to run it about anouther 450 miles and change it again with Royal purple oil and filter... 100% recommend

Hands down, Royal Purple’s the best oil I’ve ever poured into my rig. Slapped some in, and my motor went from sounding like a ticked-off chainsaw to purring like a kitten—quiet as can be. Plus, I’m squeezin’ out better gas mileage, which means more cash for beer instead of the pump. Royal Purple’s never let me down; it’s the king of oils in my book!

Listen, I get it. Everyone has some automotive elixir or magic potion they swear by. "Put this in your tank, and it will be like a new car!" We all wish it were true, but in reality, there's nothing you're going to put in an engine to bring it back to life, or keep it running 500,000 miles. But I can tell you this with complete honesty: Royal Purple was (and continues to be) absolutely worth the money in my case.At around 140,000 miles, the engine of my 2008 Jeep Grand Cherokee was noticeably louder than it was in its youth. Not a terrible noise, but there was definitely a mechanical clatter that wasn't there before. I'd also started to notice that when I changed the oil, I was getting less and less back out. I'd put 5 Qts in, and 3,000 miles later I'd drain out just 3 or even 2.5 Qts. I never noticed any oil on the driveway, so I don't know if it was burning it or only leaking while running, but it was going somewhere.One morning, after I'd gotten a little lazy and went a bit past my usual 3K oil change interval, I noticed the oil pressure light starting to flicker. Checked the stick and it was just barely registering. Something had to give. I didn't want to be the guy putting a Qt of oil in his old clunker every week (in other words, my Dad).So I started looking around and saw that Royal Purple was making some big claims with their high-mileage oil. Rejuvenating seals and cleaning your engine, that sort of thing. I kept doing more research, and the surprising thing was that more and more people seemed to be backing it up. What finally convinced me to make the switch was a YouTube video where they took the valve covers off an old engine before and after running Royal Purple through it -- there was no denying it looked cleaner inside.So I spent the money, even got the proper filter. Went ahead and did the shorter interval for the first change that they recommend to get the loose stuff out of the system before really settling in to the fully synthetic oil, even though it meant spending double. I figured if it worked, it was worth the money.Well, that was over 20,000 miles ago, and I'll be damned if things haven't improved. The engine is without question quieter, and at idle, is noticeably smoother running. But the best part is that the oil loss has been reduced dramatically. Now when I put in 5 Qts, I get 4 Qts back out. It's not perfect, but considering nothing has changed other than the oil, I think that's a big win. I no longer have to religiously check the dip stick every week for fear of an empty pan before the kid needs to go to school.End of the day, I'm just one guy who enjoys fiddling under the hood from time to time. I'm no expert, I can't tell you how or why things improved with Royal Purple. Maybe it's all just coincidence? All I know is that it's worth it for me to keep spending the extra money. I want to keep my engine running as well as possible, for as long as possible, and to me that means always using Royal Purple.

Had a slight lifter knock after using this product noise went completely away sold on Synthetic oil also was on a Subaru forum asked if anyone sent it in against amsiol and got a reply back that It was close but absolutely still the best then again look how long they have been synthetic

Most of the time you can't tell the difference in oils by how smooth your engine runs but Royal Purple does exactly that. I like it a lot!

I have had my Accord since new so about 18 years now. I know it pretty well. It's getting up there in mileage so I gave this a try. I wasn't looking for a performance increase but I'm pleasantly surprised. I know it's easy to think placebo effect but before the oil change my car could just barely chirp the tires gunning it from a stand still. Now I can floor it and spin the tires. It feels stronger passing on the highway and it idles smoother. I went from the recommended 0w-20 to a 5w-30 so maybe that has something to do with the increase in power and smoothness. I'm going to just change at 5k. At this price, I'm fine with a shorter interval. Cheaper than another Accord and I think I can drive this thing until they outlaw gas.