Mobil 1 15W-50 for 25HP Kohler twin?

Status
Not open for further replies.
Joined
Jan 19, 2003
Messages
55
Location
NC
I have a 2002 Scotts GT2554 garden tractor made by John Deere. This model is now painted green and sold as the John Deere G100. The engine is a 25HP Kohler Command v-twin. The manual calls for 10W-30 or 10W-40 for the temperature range in my area. I plan to use Mobil 1 as soon as the engine reaches 25 Hours. I am thinking of using the 15W-50 in the summer and 10W-30 in Winter. Would the Mobil 1 15W-50 provide better protection for this big air-cooled v-twin during the hot summer months?
 
i'm not sur if mobil 1 comes in a 10w40 formula but i might be mistaken. one of the main advantages of a synthetic is the wide range of temps it will protect a motor in. i would use the mobil 1 10w30 after you get the 25 hrs in on the dino oil, and leave it at that. don't worry about switching vis in the relativly mild carolina seasonal climate changes. it's alot like where i live, in va beach, va.
cool.gif
 
as penz pointed out, you can stick with one all year round. the 15w50 will work in the cold weather as well as hot. Being a synth, it shouldn't have much if any cold weather cranking problems, since I doubt you'll be out there in subzero weather with that thing.
 
Since you from NC I would run the 15/50 year round. It doesnt get cold enough in your area to worry about cranking issues. I use a 15/40 dino oil in mine year round and I am in MI where it gets much colder than your area.

[ January 21, 2003, 10:18 AM: Message edited by: blano ]
 
mracer as you can see from the wide variation in informed opinions already expressed, either weight would suffice. While 10W30 will probably give you all the wear protection your motor would ever want, 15W50 will give you a little more ... but will also add that much more hydrodynamic drag on the motor. Will you ever notice this slight, power-robbing effect? Probably not.
dunno.gif


If it were me, I'd use the thinner, recommended weight for the first couple of years while the tractor is under warranty and the motor is relatively tight.

After the warranty period is over with, I'd go with a slightly thicker oil since you are in a fairly warm climate. You can use the Mobil 1 15W50 if you want but I'd go with a 15W40 gas/diesel oil if you're going to change it once each year. Either Delo 400 or Pennzoil Long Life are easy to find and will work well. I am switching all my machinery over from Delo 400 to Schaeffer Supreme 7000 15W40 ($3 per quart) but that stuff is harder to get.

Anyway, as most of us know, the rest of the mower will break, rust or fall apart long before the motor expires even if you only take halfway decent care of it.
wink.gif


--- Bror Jace
 
A 15w-50 is too thick for this motor ....

I run either a 0w-30,5w-30 or 10w-30 synthetic in my 1993 John Deere - with 525 hours on it - and it works fine. I did the same thing in my 1976 Rally Roper, with an 11 hp B&S engine. The B&S engine still runs fine, but the rest of the mower is falling apart from old age and fatigue
frown.gif


My John Deere has a 17 hp, air cooled Kawasaki commercial engine with a fully pressurized oil system and a spin on filter - it holds about 2 quarts of oil. I typically change oil once a year - about every 50 hours - even though the old stuff still looks very clean. It also has a hydrostatic transmission that calls for a Ford Type F transmission fluid. I plan on changing that over to the Amsoil "supershift" transmission fluid as soon as I have the time ....

I'd run either the Mobil 1, 10w-30 or their 10w-40 motorcycle oil if you can find it. You could even run the Mobil 1, 0w-40 in there, but it would probably shear down a bit ....

TooSlick
 
If the motor has a pressurized lube sytem Tooslick may be right on the viscosity thing. Most of the mower engines I have delt with use a splash lubrication sytem. For this type of motor thicker 15/40, sae 30, sae 40 oil is a advantage IMO.Also these oils tend to have more zddp anti wear which is of benifit to a a/c motor.

[ January 23, 2003, 01:36 PM: Message edited by: blano ]
 
I have the same engine as TooSlick, a Kawi 17Hp twin on an ExMark 1748. I've been using Delo 400 SAE 30 (API-SJ), under the increased antiwear additives theory. All in all, no matter which oil you use, it probably won't make much difference in engine life, as long as you change the oil and keep your air filter clean and tight.

I would recommend changing that oil a couple of times before the 25 hours: Both I and my brother (another Kawi) noted debris (metal!?) in our oil drains after <5 hours of use, which later were not apparent.
 
Sorry I didn't give specifics on this engine. It is fully pressurized and uses a spin on filter that looks just like a small car filter.

I changed the oil for the first time the other day at 5.5 hours. I put in Mobil drive clean 10W-30. So, you think I should change it again at 10-15 hours and again at 25 hours?
 
I'd change it again before too long. Dad bought a new pressure washer with a Honda 5hp motor on it. I changed the oil after about 5-6 hours and it was FULL of pretty sparklies.
shocked.gif


I put Delo 15W40 in it and will change it again after it has a few more hours on it. Been -10F to 20F (max!) around here so too clod to use the pressure washer.
spaz.gif


--- Bror Jace
 
I used Mobil 1 15W50 last summer for a short period of time last summer in a B&S 20 Hp. While the engine temps didn't rise, the engine didn't develop the RPM and torque I thought it should, so I changed to Schaeffer's 15W40, and it ran much better. The 40 weight oils seem to be the upper limit for these engines.

I run Mobil 1 10W30 SS (with 132) in late fall and winter in the same engine for better starting
since the starters do not develop the torque as do automotive engine starters.
 
I took a mower into a shop, the guy said I was abusive since I had used 20W50 (yes I live in Canada but it's not like I was mowing under 45 F!)He didn't care that it was premium or synthetic, if it wasn't straight 30 it was no good. What a turkey. He WAS wrong, right? Aren't B&S engines under 6 hp prone to run rather hot anyway? I think that I heard that one time.
As goofy as I am about synthetics, doesn't it make more sense to run the thing a while in spring, drain the oil, replace with under 1 quart, and do that once a year?
I'm all ears so lets talk about it.
 
Originally Posted By: MolaKule
I used Mobil 1 15W50 last summer for a short period of time last summer in a B&S 20 Hp. While the engine temps didn't rise, the engine didn't develop the RPM and torque I thought it should, so I changed to Schaeffer's 15W40, and it ran much better. The 40 weight oils seem to be the upper limit for these engines.

I run Mobil 1 10W30 SS (with 132) in late fall and winter in the same engine for better starting
since the starters do not develop the torque as do automotive engine starters.



I have a 16 HP Briggs Vanguard V-Twin.

Here are the results of some tests I recently ran. The engine has 500 hrs on it. Normal RPM warmed up is 3600 per manufacturer..

Brad Penn 30wt 3800 cold and 3600 hot.

10W-30 Conventional Penzoil 3700 cold and 3800 hot

Mobil- 10W-30 EP Runs 3650 cold and hot.

Mobil-1 5W-30 Runs 3660 cold and hot.

Amsoil ASE Runs 3660 cold and hot

Amsoil 0w-40 Runs 3700 cold and 3650 hot

Mobil-1 20W-50 V-Twin Runs 3450 cold and 3600 hot.

Mobil-1 15w-50 Runs 3660 hot and cold.

Motul 15W-50 Runs 3660 cold and 3750 hot.

50/50 M-1 15W-50 and Motul 15W-50 Runs 3660 cold and 3700 hot.


My conclusion is that a 15W-50 oil is the limit of getting the highest RPM and perhaps the highest RPM is an indicator of the product that reduces friction the most. Using a 15W-50 synthetic in the summer is one of many good choices. A 20w-50 is too heavy.

Sent in a Blackstone with the M-1 and it showed zero wear #'s.
 
Last edited:
A governor is a device that controls the speed of the engine as the load changes. As the load slows the engine down, the governor opens the throttle to return the engine to a set speed. Governors are commonly used on engine-powered electrical generators where constant speed is important. Two types of governors are installed on small engines: mechanical and air-vane.

A mechanical -- also known as a counterbalance or flyweight -- governor uses the centrifugal force of the engine's rotation to measure the load on the engine. This measurement is matched to the setting of an adjustment nut. If the load on the engine falls below the setting, a spring opens the throttle and speeds the engine up. An air-vane governor uses the air from the rotating flywheel to determine the speed of the engine. Caution: An incorrectly adjusted governor can cause the small engine to operate at excessively high speeds and damage or destroy it.


A heavy viscosity can put a load on an engine thus lowering RPM unless the govenor can boost it past the point of resistance.

If an oil is light or has friction additives it allows the engine to go to the maximum RPM of the govenor parameters.

+/- 50 RPM is therfore possible. This is within the accuracy of most govenors. They can not precisely keep an RPM exactly on the RPM set. They are not static but rather dynamic devices and set to parameters.

Using the same engine in this mini-test with different oils and viscosities is relatively accurate as Molucule suggests in his statement previously seen on this thread.

Note that Motul 15W-50 gives max RPM; just like running a 10W-30.
Obviously it has great anti-friction properties and probably no viscosity enhancers and gives a true 15W from the get go with 50 wt protection.
 
Last edited:
Status
Not open for further replies.
Back
Top