10W-40 or 20W-50??

[blsnelling]

I have a '00 Kawasaki Vulcan 1500 Classic. It is a water cooled V-Twin. I'm trying to decide whether to run M1 10W-40 or 20W-50 motorcycle oil. It is a water cooled V-Twin. I have been running 10W-40 but thought I might go with the 20W-50 since I only ride it in warm weather and have a heavy wrist. Comments?????

 

[nick778]

I just sold my '99 Classic 1500 (didn't want to contend with the plastic oil gear issues for that year). My experience is that the bike runs much better (revs, shifts and starts easier and runs cooler) using a high quality 10w-40 motorcycle synthetic like Amsoil or Mobil 1. As these engines as also somewhat carbon prone, the synthetic helps keeps the rings, etc clean with also less varnish build-up. The amount of extra is really nominal, all things considered, for what you get in return. 20w-50, especially non-synthetic, is really for V-twins that have no water cooling and have larger clearances.

 

[JonS]

Go with the 10w-40. 20w-50 is for large air cooled v-twins.

 

[arkainzeye]

i read where amsoil and other oil companies say to go with the 10w40, because since your bike is a Metric cruise it is built with tight clearances and doesn;t need a Thick oil like 20w50. I use 10w40 in my vulcan. I used to use 10w40 amsoil motorcycle oil. but now just use 10w40 amsoil high proformance oil. Clutch Never slipped yet while using this oil with fiction modifiers...

 

[msparks]

concure 10w40.

Unless your oil sees temps over 225 for extended periods 20w50 is not needed.

This is straight from the Reline site:

quote:

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Red Line 15W50 & 20W50: The ultimate high-temperature protection in Red Line engine oils recommended for street use. Good for engines that regularly run very high oil temperatures. Best for engines that run large clearances such as air-cooled engines or large-displacement, all-out racing engines that see occasional street use. Provides 25% more viscosity in bearings than petroleum 20W-50s. Not recommended for use in cold climates where temperatures are at or below 10°F or -12°C. Not recommended for street use in production engines that see sustained oil temperatures below 225°F. Those engines should use Red Line 10W-30 or 10W-40.

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Hope this helps

 

[GeorgeCLS]

RE 10W-40 Mobil 1 MX4T, I concur.. The 50W robs horsepower, creates heat, etc. One of the many positive aspects of the full synthetic is that it is very temperature resistive.. Every jet engine using Mobil Jet II is running essentially a 5W and it withstands temps very much higher than summer heat, day in, day out..
With synthetics we need to optimize the viscosity for the engine design and as indicated in the previous post, your higher revving, closer tolerance engine needs the 40W.. A large, slow revving, loose, V-Twin, yes, the 50W V-Twin Mobil 1.
George