As many of you familiar with my posts already know, I have been a fan of using Motorcycle oils in small air-cooled engines, over PCMO or HDMOs, for the following reasons:
1) The type of engine (small, high-revving, air-cooled) is closer to the operating environment of a motorcycle than a Passenger car or even a diesel engine - therefore motorcycle oils (in theory) should be well-suited to this type of use.
2) Motorcycle oils contain significantly elevated levels of anti-wear additives, well-above PCMOs, and most HDMOs.
3) Motorcycle oils contain additional anti-corrosion additives to reduce corrosion during times of non-use. This is also a good fit for most small engines.
I've been using Amsoil MCT (10W-30 Motorcycle oil) for this purpose. Amsoil has come out with a new motor oil that I believe should be even better! It's called ZRT 10W-30. See the link to it here.
In comparing this oil to the MCT I've been using, revisiting the points above:
1) Small, High-Revving engines: In comparing MCT with ZRT:
a. Flash Point - ZRT: 453 vs. 450 for MCT
b. NOACK - ZRT - 5.2 vs. 5.89 for MCT
c. HTHS - ZRT 3.6 vs. 3.52 for MCT
Judging from this, it should be well-suited to hot, air-cooled, high revving engines.
2) ZRT contains elevated levels of Zinc and Phosphorus - 1200-1400ppm according to Pablo, which is similar to MCT
3) ZRT contains additional rust and corrosion inhibitors, just like MCT
4) UNLIKE MCT, ZRT contains friction modifiers (I confirmed this with Amsoil Tech Support). This should allow the engines to rev more smoothly, and possibly improve fuel economy.
5) ZRT is a heavy 10W-30, at 11.8 vs. 10.9 of MCT.
ZRT has a lower TBN than MCT (9.0 vs. 11 for MCT), but in the UOAs I have done, TBN is not a significant issue in small air cooled engines. When I ran both Mobil 1 and MCT for an entire season, TBNs of both oils still came in at over 9.0.
So: I think I have found the new oil I am going to use in my small engines at the end of this season!
1) The type of engine (small, high-revving, air-cooled) is closer to the operating environment of a motorcycle than a Passenger car or even a diesel engine - therefore motorcycle oils (in theory) should be well-suited to this type of use.
2) Motorcycle oils contain significantly elevated levels of anti-wear additives, well-above PCMOs, and most HDMOs.
3) Motorcycle oils contain additional anti-corrosion additives to reduce corrosion during times of non-use. This is also a good fit for most small engines.
I've been using Amsoil MCT (10W-30 Motorcycle oil) for this purpose. Amsoil has come out with a new motor oil that I believe should be even better! It's called ZRT 10W-30. See the link to it here.
In comparing this oil to the MCT I've been using, revisiting the points above:
1) Small, High-Revving engines: In comparing MCT with ZRT:
a. Flash Point - ZRT: 453 vs. 450 for MCT
b. NOACK - ZRT - 5.2 vs. 5.89 for MCT
c. HTHS - ZRT 3.6 vs. 3.52 for MCT
Judging from this, it should be well-suited to hot, air-cooled, high revving engines.
2) ZRT contains elevated levels of Zinc and Phosphorus - 1200-1400ppm according to Pablo, which is similar to MCT
3) ZRT contains additional rust and corrosion inhibitors, just like MCT
4) UNLIKE MCT, ZRT contains friction modifiers (I confirmed this with Amsoil Tech Support). This should allow the engines to rev more smoothly, and possibly improve fuel economy.
5) ZRT is a heavy 10W-30, at 11.8 vs. 10.9 of MCT.
ZRT has a lower TBN than MCT (9.0 vs. 11 for MCT), but in the UOAs I have done, TBN is not a significant issue in small air cooled engines. When I ran both Mobil 1 and MCT for an entire season, TBNs of both oils still came in at over 9.0.
So: I think I have found the new oil I am going to use in my small engines at the end of this season!