Recommended oil for 50cc - cold weather  By  michaeljc70 (Read 10,144 times)

I run castrol gtx 5/30w for break in. on my new scoot changed oil as soon as I got it then changed again at 50mi., again at 150mi. then 250. Every 750mi. after that. After the 250mi full synthetic oil.
Castrol Edge Titanium oil, I'm a castrol guy, U can use whatever you want. I found that castrol works very well in every vehicle.
Winter I run with 5/30w
Summer 10/30w

multi grade oil was created to make it easier to spin the engine fast enough to start it with the starter when real cold. for cold climates run 5-XX or 10-XX multigrade oil and get the biggest battery you can fit in. richening up the idle for winter helps it start easier in really cold weather too. Just gotta remember not to let it sit idling too long or it'll foul out the plug. ( and remember to readjust carb idle mixture back once the cold season is over. )

If you'd be running 5W30 vs 5W50, you'd have way less actual oil with 5W50 in your engine, and much more thickening agent in there.
That thickening agent does nothing to lubricate your engine, and the further the numbers are apart, basically the more even the viscosity of the oil, but the worse the quality and lifetime of the oil is.

5W20 is about the lowst I'd put in a scooter, only for those who are running in bitter cold regions always below freezing point.

I personally don't like 5W30, 10W30 gives you more actual oil, and as long as the engine can start fine on a cold engine, there's no need to go lower (like 5W30 or 5W20).
Basically to determine what kind of oil is best for your scoot, is to take an average cold day, on a cold engine, and if it doesn't start well (not a starter or battery issue), then take a step down.

In most cases, on an air cooled 50cc engine, and between 45-65 degrees, 10W30 is good oil.
10W40 does nothing to improve this. Only go up in the last number (eg from 10W30 to 10W40), if you notice too much engine vibration
while riding.

Even in the hottest regions, (with + degrees weather), and on a 4 stroke 50cc, I would not recommend anything beyond 15W40.
Getting too thick oil, regardless of outside temperature, will degrade performance.
Getting too thin oil, could wear out the engine faster, cause vibrations that may cause bolts to come loose, and parts like cables or hoses to break or wear out sooner, and too thin oil sometimes makes you loose compression, because of lousy piston ring sealing.

Besides, if you choose too thin oil, like 5W20, and the temperature is hot, and the engine is a small 50cc (or BBK) aircooled engine, you'll notice some of the oil to evaporate through the exhaust.
And if it does, causes spark plugs to be black, and valves to have carbon deposit on them.
And when valves have carbon deposit on them, they don't close as well, resulting in compression loss, which results in performance loss, and the adjustment screws will wear out faster, as the valve will start to not close as well anymore; making it necessary to do an earlier valve adjustment than normal.