[Turbo DV8]

Neither of my Honda delaers carries the Honda GN4 in 10w-30 weight. They carry that weight only in full synthetic. The selling dealer told me they prepped the bike with GN4 10w-40. I told them the manual specifies only 10w-30. They said either 10w-30 or 10w-40 is OK. But neither the Helm or owner's manual even hints at using 10w-40 under any condition or climate. Clearly, there are more motorcycle-specific oil choices in the 10w-40 weight. Did my dealer just throw in whatever they had because they didn't want to wait to order the 10w-30? Input, please?

 

[r100]

The main difference is that 10-40 will keep its lubrication qualities at higher temperatures, hence the 40 designation insted of 30.
The first number, 10, refers to viscosity when cold.
I think there are more motorcycle specific oils available in 10-40.
For what it's worth, I have used BelRay 10-40 in a number of Japanese bikes since the 80's without any oil related problems.
As long as it is motorcycle specific oil and a quality brand you don't need to worry.

 

[250 Tom]

The main difference is that 10-40 will keep its lubrication qualities at higher temperatures, hence the 40 designation insted of 30.
The first number, 10, refers to viscosity when cold.
I think there are more motorcycle specific oils available in 10-40.
For what it's worth, I have used BelRay 10-40 in a number of Japanese bikes since the 80's without any oil related problems.
As long as it is motorcycle specific oil and a quality brand you don't need to worry.

I agree. Wont hurt a thing

 

[qlred]

I've only used the 10-30. My car takes 5-20, would I put 10-40 in there- no. It's a modern motor with tight tolerances. Thicker oil may decrease gas mileage. The bikes in India say 10-40 is good I think.

 

[sendler]

10w40 seems to be the most common motorcycle oil for every brand. I have been using Mobil 1 4T 10w40 since the first oil change. Motul and Revsol make a 5w40 synthetic. I can't recall seeing any maker offer a w30 synthetic. Air cooled Harleys get 20w50. If no one makes it, you must not need it.

 

[Metalstorm]

I've been using 10-40 in mine since the first service. It's the only thing the dealership has and as was said, it has a better range than 10-30. It can handle hotter temperatures and works the same as 10-30 in the cold.

The mechanic and the parts guys were all scratching their heads wondering why the 250 shipped with 10-30 because every other Honda bike they've ever received, past and present, was shipped with 10-40 weight.

 

[CBR250R]

10w40 seems to be the most common motorcycle oil for every brand. I have been using Mobil 1 4T 10w40 since the first oil change. Motul and Revsol make a 5w40 synthetic. I can't recall seeing any maker offer a w30 synthetic. Air cooled Harleys get 20w50. If no one makes it, you must not need it.

I'm running Amsoil 10W-30 synthetic (motorcycle specific) in my bike. Purchased a box of it which should last me a few years.

http://www.amsoil.com/storefront/mct.aspx

Mike

 

[Badger]

Ditto on the Amsoil.

regards
Badger

 

[sendler]

I'm running Amsoil 10W-30 synthetic (motorcycle specific) in my bike. Purchased a box of it which should last me a few years.

AMSOIL - SAE 10W-30 Synthetic Motorcycle Oil (MCT)

Mike

Looks good. I just did an oil change but I will try that one next time to see if I can squeeze another percent out of my fuel economy with the lighter weight. The 0w20 claims 3% but that is too light for summer weather and the possibility of premature wear isn't worth it. That is a lot of gain for a spec racer though and would give you an advantage. We are lucky to get a 10% power increase out of changing the pipe.

 

[CBR250R]

Looks good. I just did an oil change but I will try that one next time to see if I can squeeze another percent out of my fuel economy with the lighter weight. The 0w20 claims 3% but that is too light for summer weather and the possibility of premature wear isn't worth it. That is a lot of gain for a spec racer though and would give you an advantage. We are lucky to get a 10% power increase out of changing the pipe.

Actually - I had fuel economy in mind when I went with the Amsoil 10W-30. I was running Mobil1 10W-40 synthetic motorcycle oil too, which did the job fine, but I decided to switch with the hope of obtaining an incremental increase in fuel economy. I had to order the Amsoil online, as I couldn't get it locally. All my bikes have 10W-30 as a recommended oil so it's convenient too.

Mike

 

[spdklls]

My dealer tried to give me 3 quarts of 10-40 when i went in to buy materials for an oil change..It's really disheartening when they dont know the simplest things about the bike at the Honda Powerhouse Dealer you bought your bike from...I made them give me 2 quarts of 10-30 instead and they still insisted I would need 3 (???morons???) but they also charge $110 for an oil change when the parts for it costs less than $20..and since I had them change it at 1st service, maybe I'm the moron

 

[Brian]

DV8 the owners manual in text says 10-30, but on the temperature scale it shows 10-40 at the higher temps.
One dealer I called to buy 10-30, said they dont stock it because of our location, so. cal. I ordered the amsoil full synthetic 10-30 for cooler weather. If I find myself idling for long periods in so. cal. traffic (like not in the mood to lane split) above 80 degrees, I will splurge on a few quarts of amsoil full synthetic 10-40. I agree that it really probably does not matter for so. cal., up north maybe get the 10-30.
BTW amsoil has a good white paper comparison and testing methods of different motorcycle oils.

 

[shahbaaz_k]

I've only used the 10-30. My car takes 5-20, would I put 10-40 in there- no. It's a modern motor with tight tolerances. Thicker oil may decrease gas mileage. The bikes in India say 10-40 is good I think.

10-30 recommended by the Honda mechanic here in India..

 

[Strelok89]

In israel the dealer insists on putting agip 10w-40 4t city
any other oil need honda israel headquaters approvment or the warranty will void

 

[Turbo DV8]

I can't recall seeing any maker offer a w30 synthetic.

Actually, 10W-30 is only available from my Honda dealers in a full synthetic!

 

[mnguyen84]

10w-40: 10w refers to the oil's ability to not freeze. The lower the number, the better it is able to withstand cold temps. 40 refers to it's viscosity. 10w40 would be thicker than 10w30.

40 viscosity will work just fine in the bike. It is the more popular than the 30 in terms of availability and practicality. 40 grade oil has the potential of working in anything from cars, motorcycles, to tractors and semi-trucks, depending on how its formulated. 30 grade is too watery for tractors and semi-trucks. So that's why 40 grade is more popular.

if you're ever at Walmart, browse the oil section for Chevron Delo 400 oil. You can compare the credentials of the 10w30 vs 15w40.

 

[jkv357]

Whoa - lots of conflicting opinions on oil I see.

It's funny how many people will say "Honda designed the engine and wrote the manual - do you think you know more than they do?" and then will run any oil that's cheap and easy to get.

A 10W-30 oil is 30 grade at its operating temp - 212 degrees. Below 212 degrees it's between the low (10) and high rating (30). Running a heavier oil than required will increase the oil pressure and decrease the oil flow - not necessarily an improvement.

The only reason to run a heavier oil than the standard recommendation is if you are operating the engine at a higher oil temp than 212 degrees. At that point the viscosity of the oil is lower than its rating - and so is the engine's oil pressure. Going to a higher grade oil will bring the oil pressure back up to where you want it.

The CBR was designed to use a 30 grade oil. The oil pressure and flow are maximized for a 10W-30 oil - unless you are consistently running the oil temp (not water temp) above 212 degrees. That's probably only optainable on the race track (constant high RPMs) on a hot day - not during normal use.

Use a 10W-30 synthetic - Honda, Redline, Motul, Repsol, Amsoil, whatever. Synthetic has significant advantages and the CBR doesn't hold much, so it's not like it costs you that much to use it.

 

[tollarja]

I'm going to drop a nuke on this thread...I just put in Mobil 1 10W-30...for CARS!

OMG, how long do you think my bike will last? One mile? Nope, I've gone over a hundred so far and it hasn't blown up. The clutch still works. Molybdenum is actually in some "motorcycle only" oils. The only thing I noticed is Mobile 1 10W-40 for motorcycles felt smoother when it was fresh, I think viscosity is responsible for that. I couldn't find 10W-40 at Walmart otherwise that is what would go in. Sportbike rider did a chemical and physical test of oils and low and behold, the motorcycle and car oils had the same shear resistance. Motorcycle had a bit more or less of the same additives. I'm betting that it is the oil that does most of the work.

Dropping some knowledge:
Oils Well That Ends Well, Part 1 - Sport Rider Magazine
Oils Well That Ends Well, Part 2 - Sport Rider Magazine

In my research I have found all of the common reasons why I shouldn't use motor oil in my motorcycle defeated one by one. However, there is only one brand that I trust because of it's retained viscosity, confirmed with several sources, and that's mobil 1.

Oh, so I actually address the OP, I ran 10W-40 for nearly 9,000 miles in hot (94F) and cold (below 32F). The only time I think the bike had 10W-30 in it was the first 100 miles. I tried to find motorcycle specific 10W-30 too, but failed. Having 10W-30 in it now, I'd rather it was 10W-40 because it just felt like it was a little smoother.

 

[jkv357]

Page one of the article you quoted states:

"The reason the old-timer may suggest thicker oil is because in older engines with higher tolerances, thicker oils were necessary to keep oil pressure up. Others believe the use of higher viscosity oils results in better protection because high-performance engines are harder on oil. This isn't true in modern engines, and using oil thicker than specified can actually harm an engine. Internal oil passages and galleys may not be large enough to allow thicker oils to penetrate and flow as well, which can possibly cause starvation. In fact, many race teams use the thinnest oil possible to gain extra horsepower by lowering the parasitic losses that occur when using thicker-than-necessary oil. The higher film strength offered by synthetic base stocks helps racing engines survive even endurance races when running ultra-lightweight oils. Of course, these engines are typically rebuilt after each race, so we do not suggest using a racing oil in your streetbike. Refer to your owner's manual and use the viscosity of oil corresponding to your riding conditions as specified by the manufacturer. The manuals often have a table with various temperatures allowing you to select the right viscosity."


That's says - don't go up in oil weight unless it's required.

Here's a Mobil 1 chart that lists the amounts of Zinc and Phosphorus in each of their oils: http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

That shows that auto Mobil1 10W-30 has only 800 ppm Phosphorus and 900 ppm Zinc. That's not great news if you have solid lifters/rockers/followers like most cycles do. For cars with roller lifters, it's adequate.

If you want to use Mobil 1 in a 30-grade oil, the Mobil1 High Mileage has better levels (1000/1100). The 0W-30 Racing is the best (1750/1850), especially if you were looking for maximum mileage, and would be worth a try. The 0W isn't a problem, rather it's an advantage. If you start-up the engine below 50 F a 10W conventional oil isn't a very good choice. 10W synthetic is better, but 5W or 0W is far superior in low temps. Oils with low "W" ratings flow better and easier all the way up to their top rating (30) - that's how they give you better mileage. Most of the time they are somewhere in between the low and the high rating.

I'm not overly concerned about the Friction Modifies that may cause clutch slipping, it's the low levels of Phosphorus and Zinc, and the possible damage to cams and lifters/rockers/followers, that are the problem with current auto oils.


Jay

 

[hondafan]

I agree with everything you have said. 10/30 Jaso MA oil is very hard to get, as it is a relatively new viscosity where bikes are concerned. I doubt 10/40 oil is going to damage anyone's engine or transmission. I personally feel that the extra polymers required to get that 30 point spread are more of a concern than the extra 10 point increase in viscosity. As you say, the pressure will increase, and that will also increase the flow. But the 10/40 will have less oil in the bottle than 10/30 due to the extra polymers.