what does 20w50 mean

20w50 is thicker when hot, so it’s better for high heat and older engines with looser tolerances. I switched to it in my 2001 Rancher and noticed less noise on hot days. Stick with the manual.

I run 10w40 year-round in my Kodiak 450 and never had issues. Unless you’re riding in extreme heat or your engine is worn, 20w50 might be overkill and could cause cold-start drag.

Actually, 20w50 can be harder on startup in cold weather because it’s thicker. If you ride in temps below 40°F, I’d stick with 10w40 or even 5w40 synthetic. Just my experience.

I agree with the cold-start concern. But for summer trail riding, 20w50 gives better film strength. I use Rotella T6 5w40 synthetic in my Sportsman 500 and it covers both ends.

The manual is there for a reason. Honda engines of that era were designed for 20w50 in warm climates. I’d follow it unless you’re in a cold region. Cheap insurance.

I’ve rebuilt a few Foreman 450s. The oil pump and bearings are built for 20w50. Using thinner oil can lead to low oil pressure at idle when hot. Just my two cents.

I run 20w50 in my 2004 Foreman and it’s been fine for 5 years. No issues starting in 50°F weather. If you’re in a deep freeze, maybe switch, but otherwise it’s solid.

Disagree with the guy saying it’s overkill. These engines run hot and the extra protection helps with ring seal. I’ve seen scoring from guys using 10w40 in high-mileage motors.

I’d check your oil pressure with a gauge if you can. That’ll tell you if 20w50 is needed. My 450 had low pressure with 10w40, so I switched and it helped.

Make sure you’re using a JASO MA rated oil for wet clutches. Some 20w50 car oils have friction modifiers that can ruin your clutch. I use Shell Rotella T4 15w40 myself.

I’ve used 20w50 in my 2002 Foreman for years. Burns a bit of oil, but no major issues. Just warm it up a minute before riding in cooler weather.

Honestly, I think 10w40 is fine if you change it often. I do 1,000-mile intervals on my Polaris and it’s still tight. The 20w50 debate is overblown for casual riders.

I’m a mechanic. For that engine, 20w50 is recommended for a reason—better shear stability at high RPM. I’d run it, especially if you’re mudding and working it hard.

I switched from 10w40 to 20w50 on my 2005 Foreman and noticed less valve clatter. Might be placebo, but I’m sticking with it. Just make sure you use a good filter too.

Don’t forget to check your clutch engagement. Thicker oil can make it a bit stiffer when cold. I had to adjust my cable after switching to 20w50.

I run 20w50 in summer and 10w40 in winter. Works great. If you’re in a moderate climate, just pick one and stick with it. Consistency matters more than the number.

I’d actually suggest 5w40 synthetic for year-round. It flows better cold but still protects at high temp. My buddy runs it in his Foreman and loves it.

If you’re rebuilding, stick with the manual for break-in at least. After that, you can experiment. But during break-in, I’d use exactly what they say.

I partially disagree with the synthetic recommendation—some synthetics can cause clutch slip in older machines. Do your research on the specific oil. Not all synthetics are equal.

I’ve seen guys run 20w50 in these for 20 years with no issues. Just change it every 500 miles and you’ll be fine. Don’t overthink it.