I want to know because is super dificult to find 10W-30 HP4M jaso t 903 MB here and the 10W-40 with the same specifications is always available.
In my experience, I wouldn't worry too much. The engines that are really picky about oil are ones with variable valve timing (oil pressure drives the cam shifting) and wet clutches, and neither applies to your bike.
Of course, you could probably get the oil from Amazon for the same price or less.
I remember Honda was planing to put variable valve timing on these (in the form of VTEC), I'm not sure if they ended up doing this.
https://www.autocarindia.com/bike-news/next-gen-honda-pcx-150-scooter-to-get-vtec-413988
I would stick to what is recommended. I'm sure the oil is available online.
I ain't no chemist so take this with a grain of salt, I could be wrong.
Before pouring in oil that you're not sure that's compatible,
first I'd check the manual to verify what OTHER oil types the engine can run on
(Most engines are rated to run on multiple different oil types, for example 2022 Ninja 125 models recommends 10W-30 but if you look further in the manual there's a graph that says that between 32 and 86 degrees Fahrenheit, it can work on 10W-30, 10W-40, 10W-50, 20W-40 and even 20W-50 according to the owners manual - BUT, I'm sure that the exact oil types are different for your Honda so please check)
IF IT CAN NOT RUN ON OTHER TYPES, USUALLY THERE'S A GOOD REASON WHY NOT. and then, just go online and try to buy it on places like Amazon or eBay - Although any bike shop should have 10W-30 as that's what, from my experience, most smaller bikes take.
Personally I wouldn't try using an oil that my engine is not rated for.
But if you are planing to try and use a different oil than what's your engine is meant to accept, then it's important to know that the viscosity ratings "10W-40" and "10W-30" consist of two elements:
- What viscosity the oil should have at -31 degrees Fahrenheit is marked with a W
- What viscosity the oil should have at 212 degrees Fahrenheit is the second number.
when you are choosing oil that's 10W-40 instead of 10W-30, this directly effects the lubrication your engine will get at it's operating temperature, while choosing 5W-30 instead of 10W-30 affects your engine's level of lubrication at cold temperature.
If you are living in a warm climate (above 70 Fahrenheit), I'd try substituting the 10W-30 for 5W-30 - the oil will be less viscous at that temperate, but it will be similar at the engine's operating temp - at your own risk.
Here's a great graph I found online with what these oil viscosity waitings actually mean in practice
Good luck!
in a perfect world, the oil would have the same viscosity throughout the temperature range. But such a lubricant does not exist. You can see from the chart that they are all thicker when cold. Modern synthetic zero weight oils (0w) are the closest we have come to a flat viscosity curve.
@mmj
That's true, but 0W doesn't make much difference - 0W does 6200 [mPA s] at -31F, while 5W does 6600 [mPA s] at -22F (source)
Also although it's the closest to flat, these charts are still very highly curled up that even with 0W-18 oil - it's viscosity at -31F would be 6200 [millipascal second] (source) and at 212F it'd be 15 [millipascal second] (source)
-
The solution I see modern cars use to avoid wear that might be caused by that viscosity difference is heating themselves using exhaust. No matter if we are talking about Toyota or VW, new complex thermal management systems that utilize an integrated exhaust manifold with an exhaust cooling system (used for heating the engine at startup)
I don't think these thermal management systems make much sense - older cars even in cold environments, even those that already have been with highly efficient engines w/o all of that thermal modern management and w/o 0W oil still last longer than any of that modern junk with overly complex thermal management.
EDIT: corrected numbers.
check your numbers again. 5w viscosity is 6600 mPa*s at -30C (-22f). This is similar to the difference between 5w and 10w.
yep that was a mistype, have fixed it. You are correct, higher viscosity rating is obviously higher.