using low viscosity rated oil in summer (ie: 5w-40 instead of 10w-40) | GTAMotorcycle.com

using low viscosity rated oil in summer (ie: 5w-40 instead of 10w-40)

5:12

5:12

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hi peeps,

i think i used a correct title, if not, let me know.

i'll use a specific oil designation for ease. what would be the negative effects, if any, for using a 5w-40 during warm/hot weather instead of 10w-40 or 15w-40 etc. notice the focus is on the first number (cold temp designation/rating).

let me add on to this, let's say the bike calls for 10w-30 for cold temps and 20w-40 for warmer temps. so 10w-40 would ideally cover the suggested oil grades for all temps, but instead of this, 5w-40 is used? since the bike calls for a 10w-30 for cold temps, will 5w-40 be simply too thin during cold temps? now what would be the ill effects if the oil is too thin?

so 5w indicates that it would be thinner in cold temps compared to a 10w. im thinking, provided that the temp doesn't drop to what the 5w is designed for, then the oil wouldn't really be as thin. does this make sense? essentially, 5w-40 would function the same as 10w-40 except in cold temps. no? and the bike wouldn't really use that '5w viscosity rating' unless the cold temp requirement for the oil is met (?).

i know some here would say follow what the bike manufacturer suggests etc etc., ok, but i would like to get some informative input here pls pertaining to the question. thanks.


5:12
 
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If your owner's manual specified 5W30, I don't know why you would want to use anything else. For motorcycling in Canada during the warm months, using a lower viscosity multigrade really doesnt offer any advantage, IMHO. If you are concerned about how quickly the oil starts to flow on startup (as in a 5W is thinner than a 10W at cold temps and thus should flow more quickly in a cold engine), you might want to consider switching to synthetic oil rather than dino oil, but keep in the viscosity range that is specified in your owners manual. I think that viscosity ranges are specified so that adequate hydrodynamic lubrication will be established on startup and while at operating temperature. An oil that is too thin may not create a sufficient oil wedge in hydrodynamically lubricated engine parts to prevent metal-metal contact. Ultimately, bearings in the engine need to have the oil wedge established quickly - if the oil is too thick in a cold engine, proper bearing lubrication will not occur, and for a fraction of a second your engine may experience metal-metal contact. Likewise, if an oil is too thin, then it will not allow a suitable oil wedge to be set up, and metal-metal contact will occur. In this regard, synthetic oils are much better than dino oils - they flow faster, are less susceptible to molecule shearing (ie: viscosity breakdown) and if they are in the correct viscosity range will provide adequate hydrodynamic lubrication - particularly at start-up with a cold engine.

Multigrade oils often have compromises - the wider the range, the greater the compromises. If this were not so, they would make 0W100 oils that would be good for all vehicles under all conditions.
 
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Guys usually run thicker oils rather than thinner... I'm not sure why you'd wanna go thinner in the summer if I'm honest. A thinner oil on start-up may not establish proper lubrication and I'd imagine on hot days it would be more pronounced... you could wear down your engine early.
 
The 5w rating just means the oil will flow better at colder temps than the 10w. Most of the damage to any engine is done at start up and even more so when it's colder outside. My bike oil recommendation is 10w40. I have no problem running 5W40 oil as long as it meets or exceeds the API rating stated in your user manual and is JASO MA certified / approved for wet clutches. These designations are what the engineers have spec'd out for the engines. The weight is just a suggestion / recommendation.

As for any negative effects, as long as you follow your API / JASO MA ratings there shouldn't be any. Now that said there are many different cleaners and detergents in varying quantities for each brand of oil one may work better than another depending on your bike. I'd say give a few different brands / weights a try and stick to the one you find feels the best.
 
They're both 40 weight oils at operating temperature - therefore there would be no difference in protection, BUT: the larger the gap between cold & hot viscosity rating, means that the oil has more additives in order to achieve this effect (i.e. 5W-40 has more additives than 10W-40).

You're thinking is a tad bit backwards: typically, you'll want to use a lighter weight cold viscosity oil in the winter, in order to aid with start-ups. For th summer months; stick to the prescribed weighted oil.

It's not an exact science, however: My car has an oil burning problem (year round), so to mitigate this I'm using a 10W-40 oil, rather than the prescribed 5W-30. It's now at 350k kms, so something's going right.
 
Kri$han said:
They're both 40 weight oils at operating temperature - therefore there would be no difference in protection, BUT: the larger the gap between cold & hot viscosity rating, means that the oil has more additives in order to achieve this effect (i.e. 5W-40 has more additives than 10W-40).
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Another point to consider....oils with a wider viscosity range (and consequently more VI improvers) tend to shear more quickly. Numerous used oil analysis results point to the regular dino Rotella T (15W-40) being a more robust oil than the synthetic Rotella T6 (5W-40).
 
oh god.. oil questions...and the myths flow like hot oil.

People with engineering PhDs figured out the correct oil grade, and its in the manual. Anything else is wrong. For water cooled modern bikes, ambient air temp does not really effect engine temps in summer, its very cold temps you have to worry about on warm-up.

If you use what is in the manual, and change when recommended, the engine will outlive you. Keep away from dealers and advice about expensive fairy-dust oil, it's all just marketing.
 
Type17 said:
Guys usually run thicker oils rather than thinner... I'm not sure why you'd wanna go thinner in the summer if I'm honest. A thinner oil on start-up may not establish proper lubrication and I'd imagine on hot days it would be more pronounced... you could wear down your engine early.
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Everyone on this forum continues to extol the virtues of Rotella T6 (5W-40), which is probably why this question is being asked. No bike I've had recommends a 5W oil, yet everyone here recommends it.
 
espro said:
Everyone on this forum continues to extol the virtues of Rotella T6 (5W-40), which is probably why this question is being asked. No bike I've had recommends a 5W oil, yet everyone here recommends it.
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Yup, my bike wants 10w-40 and that's what I'm gonna give it... I saw the T6 thread but I haven't read it.
 
espro said:
Everyone on this forum continues to extol the virtues of Rotella T6 (5W-40), which is probably why this question is being asked. No bike I've had recommends a 5W oil, yet everyone here recommends it.
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Probably because no bike usually sees starting temperatures below -20C. If they did I bet the cold weight would be lower.
 
espro said:
Everyone on this forum continues to extol the virtues of Rotella T6 (5W-40), which is probably why this question is being asked. No bike I've had recommends a 5W oil, yet everyone here recommends it.
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Ask any motorcycle mechanic if they have ever seen an oil-related engine failure. Only if the oil drained out somehow.
This stuff was relevant 40 years ago. The bike's suspension and bearings will wear out first.
 
CafeRay said:
Ask any motorcycle mechanic if they have ever seen an oil-related engine failure. Only if the oil drained out somehow.
This stuff was relevant 40 years ago. The bike's suspension and bearings will wear out first.
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Come now. There may not be a direct and immediate engine failure as a result of using improper oil, but the impact will be noticed in the long term. The difference between a bike engine lasting 80,000km vs 50,000km is found with the use of proper oil and changes.
 
thanks for the reply peeps.

so if 10w-40 is good for -5c to 40c temp range, then would using a 5w-40 oil on -5c to 40c temp range be ok too? i guess this is what actually i was after. that made my question sound simpler
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i understand that the 5w-40 can go and perform better in lower temps than the 10w-40, but with the above scenario would there be any adverse effects? my coconut is telling me that it should be ok. (again note the temp range mentioned). i could be wrong. any more thoughts on this?


5:12
 
5:12 said:
thanks for the reply peeps.

so if 10w-40 is good for -5c to 40c temp range, then would using a 5w-40 oil on -5c to 40c temp range be ok too? i guess this is what actually i was after. that made my question sound simpler
icon_smile.png


i understand that the 5w-40 can go and perform better in lower temps than the 10w-40, but with the above scenario would there be any adverse effects? my coconut is telling me that it should be ok. (again note the temp range mentioned). i could be wrong. any more thoughts on this?


5:12
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Will it work? Yes
Is it ideal? No
How big is the difference between the two? Small, but real
 
5:12 said:
thanks for the reply peeps.

so if 10w-40 is good for -5c to 40c temp range, then would using a 5w-40 oil on -5c to 40c temp range be ok too? i guess this is what actually i was after. that made my question sound simpler
icon_smile.png


i understand that the 5w-40 can go and perform better in lower temps than the 10w-40, but with the above scenario would there be any adverse effects? my coconut is telling me that it should be ok. (again note the temp range mentioned). i could be wrong. any more thoughts on this?


5:12
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Your first number, 5W, 10W, 15W - - - or 0W, is the SAE rated viscosity at the freezing temperature of water - 32 F, or 0C.
Even a 0W-30 oil is much thicker at 21C (for example) than a 20W50 is, at operating temps. Any concerns you might have, about a 5W, or 0W being too thin at "start-up" are baseless. If someone could come up with a -10W oil, I'd be all over it - summertime, wintertime - or springtime on Mars. I'm well aware of the hydro-dynamic "cushion", that oil provides and when you're starting up a cold engine, even in 30+C temps., a 5W, or 0W has it in spades. Want to prove it to yourself ? Get an oil pressure gauge and have a look at what pressure you're getting, on a cold start. Even with a 0W in your sump, you'll find that the oil is sufficiently thick, that the oil pressure relief valve is the only thing that's keeping the pressure from going over 100 psi. Ask me how I know.

Too answer the people that say, "Put in what the manual says". Absolutely - so long as "close enough is good enough".
If they were to tell you to use a 0W-40, or a 5W-40, they would be mandating a synthetic oil, because synthetic oils are the only 40's that can attain that cold viscosity. While some engine manufacturers are okay with doing that (Porsche, BMW, etc.), most aren't - hence, the 10W-40's.
As was mentioned - there are very few oil related engine failures, so long as you are using an "approved oil" and doing timely oil changes. However, there is room for improvement, if you are willing to spend some extra coin, for a superior oil. The difference may not be immediately apparent, but over the long run, it does make a difference.
 
This oil thread was doing well until:
Doug Tait said:
Your first number, 5W, 10W, 15W - - - or 0W, is the SAE rated viscosity at the freezing temperature of water - 32 F, or 0C.
Even a 0W-30 oil is much thicker at 21C (for example) than a 20W50 is, at operating temps. Any concerns you might have, about a 5W, or 0W being too thin at "start-up" are baseless. If someone could come up with a -10W oil, I'd be all over it - summertime, wintertime - or springtime on Mars. I'm well aware of the hydro-dynamic "cushion", that oil provides and when you're starting up a cold engine, even in 30+C temps., a 5W, or 0W has it in spades. Want to prove it to yourself ? Get an oil pressure gauge and have a look at what pressure you're getting, on a cold start. Even with a 0W in your sump, you'll find that the oil is sufficiently thick, that the oil pressure relief valve is the only thing that's keeping the pressure from going over 100 psi. Ask me how I know.

Too answer the people that say, "Put in what the manual says". Absolutely - so long as "close enough is good enough".
If they were to tell you to use a 0W-40, or a 5W-40, they would be mandating a synthetic oil, because synthetic oils are the only 40's that can attain that cold viscosity. While some engine manufacturers are okay with doing that (Porsche, BMW, etc.), most aren't - hence, the 10W-40's.
As was mentioned - there are very few oil related engine failures, so long as you are using an "approved oil" and doing timely oil changes. However, there is room for improvement, if you are willing to spend some extra coin, for a superior oil. The difference may not be immediately apparent, but over the long run, it does make a difference.
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I would disregard everything in this post... because it is all wrong except: " there are very few oil related engine failures, so long as you are using an "approved oil" and doing timely oil changes."
Some of it is SO WRONG it is funny.
 
bitzz said:
This oil thread was doing well until:


I would disregard everything in this post... because it is all wrong except: " there are very few oil related engine failures, so long as you are using an "approved oil" and doing timely oil changes."
Some of it is SO WRONG it is funny.
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Is that a fact ? - So, in 20 years that I've been reading up on this subject, I've gotten it all wrong ? Perhaps, you would care to elucidate - maybe point out a few things, that would show your superior knowledge, on this subject ? ? Particularly, the "funny" bits. Pretty please - I'm really looking forward to this.
 
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Bermuda said:
Come now. There may not be a direct and immediate engine failure as a result of using improper oil, but the impact will be noticed in the long term. The difference between a bike engine lasting 80,000km vs 50,000km is found with the use of proper oil and changes.
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80,000km vs 50,000 km? At those mileages the engines are barely broken in!

My 2006 Suzuki V-Strom DL650 has over 202,000 km and was ridden in temperatures from -16 to +50 using Shell Rotella 5w40. My 2012 DL650 will have 60,000 km this eve and is run on the same oil. 10-w40 is the suggested oil for both bikes. Of course to minimize wear I never sit there to "Warm up" tjhe engines but start it and go, albeit at moderate throttles and load.

Reallym, for the most part the specific oil doesnt matter as long as it's in range on the top number and close on the bottom.

..Tom
 
I'm just about to change the oil for the second time (6,000 km) and I'm thinking of trying 20W50 instead of 10W40 just out of curiousity.
Back in my country we have warm weather all year long and traffic is so bad so we always use 20W50 oil but here situation is completely different so 10W40 is the "ideal" type.

I work in downtown and sometimes I ride to work depending on the weather. Morning is fine but afternoon traffic is nuts. In a stop and go situation even when the air temperature is 12 C the engine temp will still go up to more than 100 which turns the fan on. I find that SS bike doesn't take hot temp very well and changing gear is no longer smooth when it gets too hot.

Anyone here with SS bike has the same experience and has tried switching to 20W50 in the past? Does it make any difference?

Thanks.
 
nobody said any thing about gearboxes. Op, your bike needs the heavy oil for your transmission as well.Why would you want to use a light weight oil??
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