Will using 5w20 in the summer destroy my tranny

[faltic]

Hello everyone thanks for looking at my post. I have run Chevron Supreme 5w20 in my EX250 thru the most of this winter and really like the way the bike runs with it. I change the oil in my bikes spring and fall regardless of mileage and was think of putting the 5w20 in for the spring/summer run. I'm sure this oil will not hurt the engine in hot weather (near FL GA line) but the trans is another matter. Some guy on ninja250.org has run 5w30 in his for many miles with no problem. Bike is my DD 12 mile round trip work and back no highway mostly under 9k rpm but have hit the rev limiter on occasion. Am I flirting with disaster? Thoughts, opinions and especially experiences sought.
Regards to all

 

[skyactiv]

Honda supposedly tested 5W30 in motorcycles and found it shears too much which causes transmission wear. They recommend 10W30 in many of their water cooled bikes. I think you are flirting with disaster and safety. Doesn't Kawasaki recommend 10W40?

 

[faltic]

Originally Posted By: skyactiv
Honda supposedly tested 5W30 in motorcycles and found it shears too much which causes transmission wear. They recommend 10W30 in many of their water cooled bikes. I think you are flirting with disaster and safety. Doesn't Kawasaki recommend 10W40?


Thanks for the info and yeah 10w40

 

[beanoil]

Ummmmm... Why would you run a 5w20 in an engine calling for a 10w40?
"I'm sure this oil will not hurt the engine in hot weather (near FL GA line) but the trans is another matter. "
Since the engine and trans are one unit, this statement is moot. it's all about shear in a shared sump situation. Honda knows that the engine and trans is likely to shear a 40 weight to a 30 over their recommended change interval. 10w30's at reasonable change intervals work. You are already too thin for this application with a 20.
Your thought process on running a 20 weight is just off here. Switch to a 10 or 15w40.

 

[Mr Nice]

Use what the manufacturer specs.

 

[Dyusik]

Reducing parasitic drag will feel good. I love how t6 feels after it shears out, but I dump.

 

[faltic]

Originally Posted By: Mr Nice
Use what the manufacturer specs.


My understanding is for cars the manufacturer will spec thin oil for a car delivered in the US but thicker oil for the same model delivered in the EU so evidence seems to indicated there recommendations have some wiggle room. Trust no one, LOL thanks for the reply

 

[faltic]

Originally Posted By: beanoil
Ummmmm... Why would you run a 5w20 in an engine calling for a 10w40?

Your thought process on running a 20 weight is just off here. Switch to a 10 or 15w40.


Because it starts easy and is ready to ride with choke off quickly.

See answer below for thought process clue

Thanks and Regards

 

[Ramblejam]

Originally Posted By: faltic
have some wiggle room


That's correct. 10w-40 to 20w-50.

This bike only takes two quarts - Mobil 1 Racing 4T is carried at your local Walmart, is an excellent product for this application, and your desired characteristics (super-fast ride-off time).

 

[beanoil]

Originally Posted By: faltic
Originally Posted By: beanoil
Ummmmm... Why would you run a 5w20 in an engine calling for a 10w40?

Your thought process on running a 20 weight is just off here. Switch to a 10 or 15w40.


Because it starts easy and is ready to ride with choke off quickly.

See answer below for thought process clue

Thanks and Regards

I stand by what I said. You aren't doing the bike any favors by using that light of a lube in a shared sump. It should start as easily in any temperature you'll ride in with a 10w40. Oil viscosity has no bearing on how fast you can come off of choke either.
Hey, use what you want, it's not going to blow up, just eventually wear out. But seriously, you are really too thin for a shared sump, and I would be wary of clutch compatibility long term, (depending on brand and composition of the PCMO), trans gear wear, and eventually, cam/rocker arm wear.

 

[kmrcstintn]

5w-20 pcmo is in the 'energy conserving' or 'resource conserving' category and those oils often have additives that might not be good for the clutch and cause slippage; based on that reason alone I stick with 10w-40 or 15w-40 for both of my bikes; previously used 10w-40 pcmo for short intervals in late autumn/winter/early spring for storage and low miles; usually do 10w-40 mc oil or 10w-40 atv oil (wet clutch rated) and occasionally add some 15w-40 if I have an oil change in the hottest months of summer to slightly 'thicken' the mix

had so much leftover stuff that I made a 'frankenbrew' to use for shorter OCI's this season (BelRay & Maxima 10w-40 conventional mc oil, Maxima 10w-40 symblend mc oil, Maxima 10w-40 conventional atv oil, and SuperTech 15w-40 conventional hdeo);

 

[ammolab]

So it starts good with 5W-20? Then run Shell Rotella T 5w-40 like me and many other Ninja 250 owners. I cancell the choke half a block from the house and my bike idles slow and fine.

 

[Robenstein]

5w20 is indeed very very unwise to use in that bike. As people have said you are flirting with disaster, especially in terms of the transmission and also the clutch.

As some have said, use 10w40 if you want it to live a long and happy life.

 

[Shannow]

Originally Posted By: skyactiv
Honda supposedly tested 5W30 in motorcycles and found it shears too much which causes transmission wear. They recommend 10W30 in many of their water cooled bikes. I think you are flirting with disaster and safety. Doesn't Kawasaki recommend 10W40?


The Japanese OEMS on masse did testing, and found below an HTHS of 2.9, pitting occurred in 3 out of the 4 manufacturer's products, and as you say, there was testing with 5W30s that pitted, while 10W30/40 didn't.

http://fuelsandlubes.com/digital/fli/201...html/page8.html

Now a 5W20 starts with 2.6 or 2.7 HTHS, so is already starting in the danger range before subject to shear and dilution.

 

[faltic]

Thanks for the input guys, I will us 10w40 this spring/summer but may still use the 5w20 in the cooler seasons.

 

[Robenstein]

Originally Posted By: faltic
Thanks for the input guys, I will us 10w40 this spring/summer but may still use the 5w20 in the cooler seasons.


I would not use the 5w20 at all....in any season for the reason Shannow put so well. There are 0w40 motorcycle options available to give you the thin oil on startup while still providing the protection needed at operating temperature.

 

[demarpaint]

A UOA for the 5W20 would be interesting.

 

[alarmguy]

Originally Posted By: beanoil
Ummmmm... Why would you run a 5w20 in an engine calling for a 10w40?

Your thought process on running a 20 weight is just off here. Switch to a 10 or 15w40.


My thoughts exactly, I would say to anyone running an oil like posted above, keep running the 5/20 in an engine designed for a 10/40 and report the results back to us in a few years ... )

I dont understand why people dont listen to the designers/builders of the engine. We arent talking a slight variation here, 5/20 vs 10/40, personally I think its a joke.

 

[Cujet]

The use of ultra thin oils also has another interesting downside.

The lifespan of sump lubricated chains. Hyvo and conventional chains use a hardened steel pin and steel bushing or plate with full metal to metal contact. The cam chain and balancer chains are not unlike the drive chain.

Testing repeatedly shows that chains last longer, often significantly longer, with 30+ viscosity lubricants.

In addition, contaminated oil, such as during common extended drain intervals, significantly reduces chain life. This makes sense, as the micro particulates cause wear on very tight clearances of the steel to steel interface of a modern chain.

So, in addition to the connecting rod bearing stress and lack of proper con-rod bearing hydrodynamic lubrication at extreme RPM's an ultra thin oil provides, you are very likely to be significantly reducing cam chain life.

Pick a proper viscosity, pick a high quality oil and change it often.

I suggest Mobil 1, 10W-40 motorcycle oil.

If you simply like the way the thin oil feels, just let the engine warm up for a bit before roaring off...

 

[grampi]

Originally Posted By: beanoil
Ummmmm... Why would you run a 5w20 in an engine calling for a 10w40?
"I'm sure this oil will not hurt the engine in hot weather (near FL GA line) but the trans is another matter. "
Since the engine and trans are one unit, this statement is moot. it's all about shear in a shared sump situation. Honda knows that the engine and trans is likely to shear a 40 weight to a 30 over their recommended change interval. 10w30's at reasonable change intervals work. You are already too thin for this application with a 20.
Your thought process on running a 20 weight is just off here. Switch to a 10 or 15w40.


I was wondering the same thing...why would someone run a 20 weight in a motorcycle at all? I know of none that call for oil that light...