Especially since the 372 has a larger tank than the 462: 770 vs. 720 ml.
Thank you for the anecdote.
MS 462 test stand results: max. power 406 g/kWh, max. torque 467 g/kWh, Stihl specification 401 g/kWh
372 XP X-Torque Husqvarna specification 426 g/kWh
I'm sorry, but without pointing to source documents I will treat such statements as old wives tales, plenty of which circulate on this and other forums.
And why would they single out exactly Stihl? There were quite a few more manufacturers in the market...
Moreover, Komatsu Zenoah's stratified scavenging was also not the only one developed at the time.
John Deere/EMAK tried another method of stratified scavenging called Compressed Air Assisted Injection or Stratified Charge Injection (CAAI/CWI) - US Patent 6,273,037.
Husqvarna (formerly Electrolux) only acquired the OPE part of Komatsu known as Komatsu Zenoah. The price was about JPY 18.2 billion ($155m). Komatsu is still around and manufactures many large machines such as trucks, excavators etc. (including forestry harvesters, forwarders etc.), which are used around the world.
Here we are talking about fuel efficiency, not absolute performance. A machine can be a turd but have very good fuel economy.
A BSFC map, rather than a torque/power curve, would be obviously ideal. Random example:
View attachment 1198874
But assuming we are running two strokes at WOT something like this for 357 XP would be good enough:
View attachment 1198875
q = SFC
Note that there are no dramatic differences in the value of q between the point for which torque takes its maximum value and the point corresponding to the highest power. The same is shown by the measurement results published for these two most important points (500i being an infamous exception).
Regarding MS 261 vs. 550 XP (Mark II). You can laugh at her, but as expected based on the specs, I don't see any significant difference between the two. Echo on the other hand...
View attachment 1198876
As I see it, this has devolved into another Stihl vs. Husqvarna, which doesn't really matter here.
The actual original question was whether strato saws need more oil in the mix to provide sufficient lubrication for the bearings. And that's because of the difference in fuel consumption to do the same work. I wrote that this fuel consumption is actually not that much different between strato and non-strato saws, although on average the introduction of stratified scavenging engines has probably reduced this consumption. On the other hand, other “improvements” were introduced gradually, which also found their way into non-strato engines.
For example, in the first 2 Komatsu Zenoah engines that used their idea they also changed the shape of the combustion chamber, the location of the spark plug, used a modern CDI module. They were also allowed to run leaner.
All of this resulted in reduced exhaust emissions measured according to rules set by environmental agencies, reduced fuel consumption, reduced maximum engine power and torque, increased engine temperature (and thus higher NOx emissions).
The real motivation for the introduction of engines with stratified scavenging was the looming deadlines for agencies like CARB and EPA to introduce new emissions requirements that engines without the aid of a catalytic converter would be unrealistic to meet.
OK. Another example. Results taken from a test conducted for various “cheap” chainsaws.
Stihl MS 181 (strato 1.5 kW): 360 g/kWh (Stihl spec. approx. 370 g/kWh)
Dolmar PS-35 (non-strato 1.7 kW): 460 g/kWh
Solo 643IP: 486 g/kWh
Husqvarna 135 (strato 1.5 kW): 597 g/kWh (Husqvarna spec. 652 g/kWh)
Efco MT 3500 S: 619 g/kWh
Echo CS-310ES: 643 g/kWh
For comparison a Zenoah G375AVS/G370x/G380x "clone" from the same test: 753 g/kWh
Husqvarna 135 is not some exception when it comes to saws sold under this brand by Husqvarna AB.
A few examples (all Husqvarna provided specs):
Husqvarna 130: 725 g/kWh
Husqvarna 135 Mark II: 725 g/kWh
Husqvarna 435 Mark II: 652 g/kWh
Husqvarna 440e Mark II: 513 g/kWh
Husqvarna 445 Mark II: 481 g/kWh
Husqvarna 450 Mark II: 504 g/kWh
OK. Let's see how the bottom of the line sold in the EU and US under the name Husqvarna performs.
Husqvarna 120 Mark II (1.4 kW): 428 g/kWh.
Sounds pretty reasonable... But let's see how it performs in practice out of the box. Ouch, it's probably so lean that it's virtually unusable.
I've never seen such a problem with a Stihl out of the box, which can also be seen in these videos.
Stihl specs:
MS 170 2-Mix 372 g/kWh
MS 180 2-Mix 377 g/kWh
MS 171 415 g/kWh
MS 181 370 g/kWh
MS 211 368 g/kWh
MS 241 364 g/kWh
Unfortunately, I don't yet have the data of the new Stihl turds series (162, 172, 182, 212).
Of course, Husqvarna's “pro” chainsaws are comparable to Stihl's in every way. Those at the bottom of the range are something of a curiosity. Although they are probably no worse in terms of the specifications considered here than other brands anyway.
I really recommend trying something from the 1139 series if one likes low fuel consumption. I know it doesn't get a lot of respect here, but I kept smiling seeing how rarely I had to refill while preparing firewood.
Zenoah = Redmax in the US. Unfortunately, Husqvarna has stopped selling chainsaws under Redmax name. Husqvarna 543 XP is a Zenoah design manufactured in Japan.
Zenoah G45xx/G50xx/G52xx and G375AVS/G37xx/G38xx have been basic design solutions from Chinese manufacturers sold for at least 20 years. It also has the greatest availability/price of parts.
