Viscosity Question - ST1300

kurt1305

kurt1305

Joined
Feb 24, 2007
Messages
24
Location
Austin
I see that some here are using 15W-50 or 20W-50 oil in their ST's. My manual says that 10W40 should be as high as it gets.

I noticed that my XR650L also requires 10W-40, but previous in years the manual stated that 20W-50 was fine. Honda at some point decided the heavier oil hurt their EPA stat I'm sure.

So the question is... did the ST1300 ever condone up to 20-W50 or has it always required 10W-40?
 
From what I have read the 1300 manual recommended 10-40 until 07 then they changed it to read 10-30 but retained the same viscosity chart ?

Spencer
 
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Hi, I run Shell Rotella 5W-40 synthetic in my 06 ST and I have had excellent luck thus far.
 
My owners manual shows a picture with arrows delineating what viscosity to use for what temps.
Higher viscosity is indicated for hotter ambient temps.

Mark
 
I think the US manuals only show one specified grade, and recent recommendations are more to meet mandated economy or emissions standarsd.

In most markets a range of grades is shown, based on the ambient temperatures in which you operate. In the ST11 workshop manual it has such a chart (which is exactly the same as for my 78 GS1000 Suzuki!), and this seems to be a coomon recommendation. Basically a 10W-30 operates from about -12c to 30c, but if the standard oil for an 07 ST13 is that oil, the newly specified oils must be better at handling high temperature conditions (you would hope!). Any 10W oil is good down to the same tempartures. A 20W oil is good for down to 0c in theory, but when I tried a 20W-50 in the ST11 (had some spare) it was too thick on cold mornings (5c or a bit below) in spring conditions as the gearbox took ages to shift without an effort. This would be good in a hot climate or summer though.
 
Newer engines seem to specify thiner oils. It might have something to do with oil getting better or it may have something to do with tighter tollerences in the engines not and thinker oils not getting in there.
 
The oil must be getting better as a 10W-30 would not have been recommended for general use not so long ago, and very rarely in bikes with shared engine and transmission. 10W-30 has never been said not to use, but rather don't use it in hotter conditions. EPA standards have more do do with this development. Hopefully find a motorcycle oil without friction modifiers in 10W-30 will get easier, and car oils of this grade would all be friction modified. Someone tried a 10W-30 in an ST11 and got it tested, and it did show more degradation than a 10W-40
 
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saaz said:
The oil must be getting better as a 10W-30 would not have been recommended for general use not so long ago, and very rarely in bikes with shared engine and transmission. 10W-30 has never been said not to use, but rather don't use it in hotter conditions. EPA standards have more do do with this development. Hopefully find a motorcycle oil without friction modifiers in 10W-30 will get easier, and car oils of this grade would all be friction modified. Someone tried a 10W-30 in an ST11 and got it tested, and it did show more degradation than a 10W-40
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I agree saz. It was my memory that my Hondas of the late 60's and early 70's (50, 70, and 175 cc) had 10w-40 cast right in the transmission case around the oil fill although the owners manual would have the chart showing 10w-30 to use in temps to about 80 degrees F. My '71 CB350 has 10w-40 on the oil fill hole. All these bikes share the transmission and engine oil. I do not have the original owners manual for the 350 but an aftermarket one recommends changing the oil as often as every 1000 miles.
 
I'll just stick to a 10W-40 oil. Just curious whether or not 50 weight was ever condoned on the upper end. Apparently not. Thanks!
 
I avoid the honda dealer like the plague..luckily I have in town an independent shop run by a guy who has been racing motorcycles for years and knows what he is talking about..because of the hot weather in florida he putsMotul semi synthetic 15-50W in the ST..I asked about the high number and he said because of the the ambient temps here that it would be fine and thats what he recommends..Its hard to argue with a guy who has a shop full of racing trophies and still spends almost every weekend racing superbikes.
 
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Geoff said:
hard to argue with a guy who has a shop full of racing trophies and still spends almost every weekend racing superbikes.
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One point to consider - racing engines generally get torn down and have parts replenished much more frequently than your streetbike does.
 
The manual for my '05 shoes 10w-40 preferred but 20w-50 is also approved for hotter temps. I generally run 10w-40 Mobil racing 4T motorcycle synthetic in mine. 10w-50, 15w-40, and 15w-50 would all fall within the recommended ranges in my owner's manual. I would never use a 5w-40 because the 5-weight spec falls outside of Honda's recommendations. If I were ever to have an engine problem (however unlikely), I would not want to give Honda that "out" from a warranty claim.
 
My Suzuki 78 GS1000 has 10w-40 embodied on the filler cap. 2500km oil changes, oil filter every second time. An oil cooler and modern oils means a 5000km oil and filter change, but I would not push it much past that as the transmission shift quality tells you the oil has had it. The ST11 is really easy on oil relatively.
 
Lots of people swear by dino rotella 15w-40, not me. I changed oil yesterday and used that specific oil. Bikes rpm dropped about 250 rpm and seemed like it was strugling. On the highway same thing, bike had to be pushed harder to get to desired speed. I turned around, went and bought some honda 10w-40 gn-4, it is only $5 more a gallon, changed it and now it is normal again and I can sleep better. I won't be using that heavy oil anymore unless I'll move to warm climate. BTW, it was around 70 deg yesterday. Someday I might go for rotella 5w-40, but than again, why to mess with a good thing.
 
I would run what is listed as "preferred"...10W-40. It covers the WHOLE range of ambient temps on the chart and besides it's liquid cooled, it doesn't get hotter when it's hotter out side. It stays the same. That's the job of the coolant, radiator, fans, and thermostat.

With an air cooled engine I'll run the thicker oil listed as allowed. I've owned 2 XR650L's and when you're plonking in the woods with no air going across those fins you can literally cook oil around the valves at the top.
 
I run 15w50 Mobil 1 in my ST. I get around 45-48 mpg on average. But, I do run in temps above 100 half the year. When I took the bike to the STealer for the 600 mile check, he said it would be good to put in 20w50 due to the high temps we ride in.

My 88 NX 650 , same motor as the XR, uses 20w50 only.
 
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