My RZR: 2016 RZR 900 4
Join Date: Oct 2010
Location: Lindstrom MN
Feedback Score: 0 reviews
Re: Engine Oil Options
I've run PS-4 in the 3 RZR's I've owned. I have not gone above a couple thousand miles on any of them, so I don't have high mileage experience, but I haven't had any engine issues. Generally I change my oil with around 500-600 miles which is most of my seasonal mileage. I trust the Polaris oil because they test their engines and vehicles with this oil in them. They build engines on dynos which can put significantly higher loads and abuse an engine more than any of us driving our RZR's on the trails. I have had oil analysis completed and seen significant fuel dilution just as Jimdawg shows in his reports. I agree fuel dilution is going to be the killer of the oil in these units, so changing your oil frequently is probably the best solution. Fuel Dilution will reduce the viscosity, as seen in his oil analysis, so running a high viscosity oil (50 in 5w50) should improve the life of your engine because it will handle more fuel dilution prior to reducing the viscosity to the point additional wear will occur. Maybe it only reduces the viscosity to a 30 wt when starting at 50, but if you started at 30wt it may be reduced to a 10 wt. Polaris likely sees this issue as well, so maybe that is why they use a 50wt. Ultimately they have more testing miles and hours than any of us, so if it works for them it will work for me. Buying Polaris oil and filter 1 - 2 times per year doesn't add up enough to justify potential issues due to buying an oil that may be cheaper or "easier to get" (Amazon carriers Polaris oil, so it's not hard to get).
I also agree with Jimdawg on Amsoil testing. I have read many of their reports, and they are written well and they provide data to support the claims they want to address. I have been an engineer long enough to know there is always more details behind the scene good or bad. I think they make good products, but I believe Amsoil is probably the best oil marketing company in powersports. Look at the number of races/series they sponsor to see how much money they make on the oil they sell.
2012 RZR 570 and 2015 RZR 900 Trail White Lightening - SOLD, for a 900 4.
2016 RZR 900 4 SPECTRA ORANGE, Polaris 4500HD winch, Polaris 10" light bar, Polaris Soft Roof, Nelson Rigg upper door bags, UTV Giant Lower Doors- Sold to go back to 2 seater
2016 RZR 900 S, VIPER Max4000 winch, Polaris front bumper, UTV Giant Lower doors, Polaris L&N Poly front windshield, TUSK soft rear window, Polaris soft top, Polaris L&N Cargo Box