10W-50 vs. 10W-40 Motor Oil

[art miller]

I accidentally ordered Castrol 10W-50 full san. 4T oil from Walmart. I realize the manual calls for 10W-40. Before returning this oil are there major issues if using this oil in my 2014 FJR. I do not ride in cold temps. Since the clutch and trans is lubed by the motor oil will the 10W-50 cause shifting issues? Thanks for your thoughts.

Art

 

[SkooterG]

There should be no problem. Though I typically use the cheaper 15W-40 oils, there has been many a time I have bought/used the Mobil 1 20W-50 synthetic when it has been on sale.

 

[fastpappy]

My manual called for the 20/50 which is what I have always used except for an experiment one time with Rotella which the bike didn't like so immediately went back to the 20/50. While I did ride in the cold back awhile haven't lately but often in the heat and a lot of traffic. YMMV.

 

[RossKean]

Since the clutch and trans is lubed by the motor oil will the 10W-50 cause shifting issues?

The only thing that could cause issues with shifting/clutch slippage are the friction modifiers that are present in some car-specific oils. The 10W50 should be fine if it is their MC oil.

...except for an experiment one time with Rotella which the bike didn't like so immediately went back to the 20/50...

Rotella T6 fully synthetic 5W40 is all I use in my FJR - no issues for me.

 

[art miller]

Thanks for the feedback. The 10W50 is indeed Castrol T4 full syn. motorcycle oil. I ordered only 4 quarts as I have one and 2/3 quarts of Castrol 10W40 left lover from the last 6 quart order. Any reason I should not mix the 10W40 with 10W5t0 next time I change oil? Both are Castrol T4 full san. motorcycle oil.

 

[Mihalis fjr]

I use 20w-50 semi synthetic all year since i bought the bike at 2003.Never had a problem!

 

[Old Guy]

My 2013 manual lists 10w50 as one of the acceptable grades. I'd run it.

 

[art miller]

My 2013 manual lists 10w50 as one of the acceptable grades. I'd run it.

Thanks!! That settles it. Your attached chart is helpful as I have had situations where riding in 110 F heat. The 10W50 will be even more beneficial. Walmart is out of Castrol full syn 10W40. Apparently the Forum members snatched up all their inventory.

 

[Old Guy]

Thanks!! That settles it. Your attached chart is helpful as I have had situations where riding in 110 F heat. The 10W50 will be even more beneficial. Walmart is out of Castrol full syn 10W40. Apparently the Forum members snatched up all their inventory.

Dang them guys. It's gotten hard to find what I want on the shelves when I want it here too. Luckily I'm not that picky.

 

[mcatrophy]

I can't remember a single instance of a report of an FJR motor or gearbox failure due to the use of the "wrong" oil. Use it.

 

[Old Guy]

I can't remember a single instance of a report of an FJR motor or gearbox failure due to the use of the "wrong" oil. Use it.

I've been following motorcycle forums either like this or on the old micapeak.com for, I suppose, right at 30 years, and I remember one. And from his description of his problem I suspect he had problems coming long before he changed to the oil he said caused it. If some of the oil analyses I've seen are to be believed, oil can change viscosity over time in the engine.

 

[mcatrophy]

I've been following motorcycle forums either like this or on the old micapeak.com for, I suppose, right at 30 years, and I remember one. And from his description of his problem I suspect he had problems coming long before he changed to the oil he said caused it. If some of the oil analyses I've seen are to be believed, oil can change viscosity over time in the engine.

Oil certainly changes its properties in use, viscosity, cleansing abilities and so on, let alone build-up of contaminants. Which is why it, and the filter, should be changed regularly.