The Honda PCX / Forza / ADV150 / SH Forums

I have a couple of PCX 150 , used in the tropics in Thailand gently, temperature rarely drops below 26° c = 79°f. I want to use fully synthetic 0-20w oil because available and cheap.
Viscosity is really about oil flow/temperature at start up and manufacturers have to account for people starting below freezing up to and beyond 26° c that is why they recommend 10-30w not because of any mysterious quality different viscosity oils have for lubrication.
I believe in the tropics using straight SAE rated oil would be best because the process of altering the structure of the oil to have variable viscosity reduces it's capacity to lubricate.
0-20 w oil is quite new and not a lot written about it on the boards anyone got any ideas about this proposition, have I got it all wrong ?

Unless you are going to run this engine for 15 years and then break it down to do microscopic checks, you can use any oil That's anywhere near the spec called for in the manual, 0W-20, 5w-30,10w-30, in a temperate climate, it doesn't matter. Just my opinion.

He's right..dont overthink it..

I feel that modern multi-grade synthetics lubricate better than mono-grade conventional oils. Very generally speaking, internal combustion engines like stronger film strengths to keep the metal bits from touching each other. If I lived in your climate 0w-20 wouldn't be my first choice, but I understand why you're switching.
If you've been using 10w-30 then the new 0w-20 is probably going to be a more volatile oil and will disappear more quickly. Just check your oil level more frequently.

easyrider wrote:He's right..dont overthink it..

^People can't help it.

In car motors, as we have gone from single weight oils to 10W30 to 5W30 to 0W30 and now 0W20. Here are my thoughts. The car manufacturers actually changed or redesigned the clearances on connecting rods and the crankshafts on automobile engines. Most of this is good. (better fuel economy, quicker startup lubrication) For example at 15 degrees F in Michigan the oil flows immediately.

But these scooters still can get stressed out. Imagine someone deciding to drive across the US in summer. With new parts I think it could work. The oil temperature is going up ! Yes, the connecting rod has needle bearings, but that temperature is thinning out the oil. The engine is designed to work in any climate around the world and 60% of the world is in warmer, moderate climates.

The original Volkswagen beetle ran 30 or 40 single weight oil. (air cooled engine) Motorcycle manufacturers say that fifty weight oil is OK in large bikes in the summer time. June - August.

I would be frightened by 0W30 oil in a scooter zooming across an interstate or even back road June - August. I would run instead 10-W-40 high quality synthetic instead, and sleep better in my hammock or hotel in the evening. Born in 1947

the process of altering the structure of the oil to have variable viscosity reduces it's capacity to lubricate.

This is false. The advantages of variable weight oil VASTLY outweigh the disadvantages in terms of lubrication.


0w20 is thinner than Honda recommends. I would not run it or recommend it. In your climate zone, you are better off using a w40 oil, going thicker instead of thinner, per Honda's recommendations. viewtopic.php?f=19&t=7372 outlines supported weights of oil.

In any case, a good modern synthetic is better than nothing, but you risk damaging your engine by using out-of-spec oil. Oil is cheap relative to the cost of the scooter. Use the recommended weight and don't overthink it. There's thousands of engineers who know better than you and I who specifically recommended the oil weights in the links above.