ls1mike
$50 Site Donor 2024
Heck I do it in the Caprice and Trans Am. As long as it isn't cooking oil...do it.
Can I mix oil viscosity and brand?
- Thread starter SupremePossum
- Start date
All true in theory, but it is a lawn mower with splash lubrication, not a complex automobile engine. The number of mowers I see every year that have been running with almost no oil, or the original oil and are fine is insane. Is xw20 optimal? No, and not recommended, but using it until the next oil change won't kill the engine, especially if he keeps up with the level, and that was my point.
There are cars out there running 0w20 and 5w20 with much higher oil temps than a lawn mower.Could be, maybe? For sure if you are running it near maximum output for extended periods of time, then something like a 15W40 is better. If you are mowing a few taller weeds on a dried out lawn, then anything is fine. Bogging through 8"+ of wet grass, or running 100% duty cycle on your pressure washer, probably a thicker oil more temperature tolerant oil is going to be a good idea.
Some higher HTHS numbers makes me feel better, but I have splashed some 5W20 in the 50yr old 3.5 B&S rotor tiller and its still here too.
Why is Kawasaki recommending 50 grade oil in their engine's currently just because they must have a reason. 20 grade oil is absolutely foolish to run in Houston in a OPE.All true in theory, but it is a lawn mower with splash lubrication, not a complex automobile engine. The number of mowers I see every year that have been running with almost no oil, or the original oil and are fine is insane. Is xw20 optimal? No, and not recommended, but using it until the next oil change won't kill the engine, especially if he keeps up with the level, and that was my point.
Because Kawasaki engines are known to consume oil, especially the newer V-Twins, and they want to make it through warranty, not because 20 grade will blow it up on a hot day. If 5w20 couldn't stand up to high heat, Texas and Florida roads would be littered with Hondas and other vehicles with blown engines. It still amazes me that some on this forum believe OPE to have higher demands on engine oil than modern day automobiles.
Time for oil flushes and some @High Performance Lubricants no VII oil or Redline,Amsoil 30wt
Not a valid comparison. Small air cooled engines use the oil as a part of the cooling system. Modern lean running E10 burning air cooled engines operated in high ambient temperatures (like Houston in August) at high loads (like mulching heavy grass) with a dull blade and a little grass build-up on the cooling fins for good measure can get the oil up to almost 400 degrees, WAY higher than in a water cooled engine in a vehicle. The VII in the oil will not tolerate that kind of heat before it breaks down, and the oil you are left with will not adequately lubricate the engine.
I agree, but using 5w20 for one season if he keeps the oil full (by adding some assuming it burns it off) will not blow up or damage the engine like everyone here seems to think it will. Again, it's a LAWNMOWER.
And that's the point really. Air cooled, operating at high ambient temperatures. It most certainly can damage the engine. As I noted, an engine kept full of oil that yields an insufficient MOFT will damage the engine regardless of the quantity.I agree, but using 5w20 for one season if he keeps the oil full (by adding some assuming it burns it off) will not blow up or damage the engine like everyone here seems to think it will. Again, it's a LAWNMOWER.
If I assume you have a normal yard and it takes you an hour to mow it ---
It will NEVER MATTER if your oil is 5W20 or 10W30 or 15W40 - or a mix or weights and brands.
Just check the level every once in a while and change it every year.
I had a vehicle that required SAE 30 in the summer (1981 Turbo Trans Am) I also used 15W40 in a motorcycle, 5W30 in one vehicle and 5W20 in another and also a few bottles of 10W30.
Some of these oils were conventional some synthetic.
I cleaned out my cupboard and determined I had a whole bunch of partial bottles of oil -
So I used it up in my lawn mowers - SAE 30 conventional + 5W20 synthetic and 15W40 conventional + 5W20 synthetic and 10W30 conventional + 5W30 synthetic.
Used it all up - took a few years - and I still have the mower that I used and it still runs like a new one.
I live in Houston so it is hot all summer.
Would I do this in my new Highlander? NO but lawn mowers don't care.
It will NEVER MATTER if your oil is 5W20 or 10W30 or 15W40 - or a mix or weights and brands.
Just check the level every once in a while and change it every year.
I had a vehicle that required SAE 30 in the summer (1981 Turbo Trans Am) I also used 15W40 in a motorcycle, 5W30 in one vehicle and 5W20 in another and also a few bottles of 10W30.
Some of these oils were conventional some synthetic.
I cleaned out my cupboard and determined I had a whole bunch of partial bottles of oil -
So I used it up in my lawn mowers - SAE 30 conventional + 5W20 synthetic and 15W40 conventional + 5W20 synthetic and 10W30 conventional + 5W30 synthetic.
Used it all up - took a few years - and I still have the mower that I used and it still runs like a new one.
I live in Houston so it is hot all summer.
Would I do this in my new Highlander? NO but lawn mowers don't care.
Some people on this site act like it's a sin to ask a question that's been asked before.
Why don't you ignore the questions if they bother you so much?
- Joined
- May 28, 2014
- Messages
- 2,265
It's hard not to "follow you around" when you complain about so many people's posts and seem to spend a lot of time looking up people's past posts to point out they asked the question before or list 20 similar posts to embarrass them. If I think a post is a waste of time I ignore it. Also, the 'Search' function on this site leaves a lot to be desired.
PS: I do respect your knowledge of engineering, oils etc...and the high mileage you get from your vehicles but your 'policing' of threads is quite annoying and probably discourages some people from asking questions for fear of your response.
Last edited:
I don't hesitate to mix viscosities or brands for the sump in an automobile or truck. But for a small capacity sump like in most OPE, why worry about using up a half quart of 5w-20? For your use, I'd go 10w-30 synthetic all day long.
Last edited:
I am the opposite.
My vehicles get the correct spec per manufacturer - but my lawn mower gets whatever is left over.
I did deviate some -
My wife's vehicle took 4.5 quarts of 0W20, my Tahoe used 6 quarts of 5W30.
When my Tahoe needed a little oil to top it off I would use the 0W20 left over from my wife's vehicle rather than open a new bottle of 5W30.
My Tahoe is a 2007 with the 5.3L V8 -a new Tahoe with the 5.3L V8 uses 0W20 - I have wondered if there is really any difference in the internal working of the 2007 and 2024 5.3L V8 - my guess is not much.
In any case 8 ounces of 0W20 isn't going to change the properties of 5.75 quarts of 5W30 much.
I should have qualified by saying "in an older automobile or truck."
