Multigrade yes or no in Lawn mower?

Messages
3,032
Location
Richmond, VA
While the manual says straight 30 there have been millions of folks using multi weights for years with zero problems. I have mixed weights (straight 30, 5-30, 10-30) all at once and she runs about the same. The biggest thing to consider on this type of engine is the air filter.
 
Messages
1,087
Location
Germantown TN 38138
For several years the number one recommendation of Briggs & Stratton has been synthetic 5W30 motor oil. They sell such an oil in SL formulation under their own brand name. Honda has recommended 10W30 oil in their engines for many years, with no mention of synthetic. B&S says that use of nonsynthetic multigrades in their engines might result in excessive consumption in very hot temperatures. They recommend 5W30 synthetic for temperatures from -20 to +120.
 
Messages
11,184
Location
Bad Axe, MI
In air cooled hot running small engines i like running a strait grade oil i run ACD 30w in all mine but lots of people run multi like said above,some cases you may see some usage with a multi grade oil..i would stick to a 30w.
 
Messages
388
Location
Canada
My 3.5hp Briggs and Stratton lawn mower engine is on its 32nd year of running 10w30 dino. It has lead a tough life, mowing model airfields plus many properties besides my own. Compression is down but still good enough to start and run full out, I use it strictly on the airfield now, 3 to 4 hours straight running every 2nd week, only stopping to fill the tank when required.
 
Messages
2,759
Location
CarMax
Looking at the owners manual for my Tecumseh LV series engine, it says in their oil usage chart: SAE 30W - For temps 32*F to 100*+F SAE 5W-30 or SAE 10W - For temps -20*F to 40*F SAE 0W-30 - For temps below -20*F to 40*F Also states: Using multigrade oil above 32*F will increase oil consumption. SAE 10W-40 is NOT recommended.
 
Messages
3,394
Location
Austin, TX MSA
 Originally Posted By: y2k345
Should a person use Multigrade oil in an air cooled say Briggs and Stratton engine?
Yes. All newer motors are spec'd for multigrade and I doubt that B&S has changed much. I run Maxlife 10w30 in my mower, runs great. I used 5w40 TDT in my old mower, it just about eliminated the consumption I saw on straight 30wt.
 
Messages
25,045
Location
ON, Canada eh?
As for B&S not changing much... My dad took a Carb& gas tank off an almost 25 year old B&S engine and put it on a newer one so he could get rid of the governor and run it richer for a project of his, and it fit just fine and worked great with some modification. The insides of the new engines look almost identical as the old ones... ;\)
 
Messages
39,781
Location
Great Lakes
 Originally Posted By: 1999nick
For several years the number one recommendation of Briggs & Stratton has been synthetic 5W30 motor oil. [...] B&S says that use of nonsynthetic multigrades in their engines might result in excessive consumption in very hot temperatures. They recommend 5W30 synthetic for temperatures from -20 to +120.
Interesting. I recently asked Toro about the oil for my new mower (B&S engine), and they stuck by the owner's manual regurgitating that I should follow the recommendation which came from B&S - it says to use straight 30-weight and nothing else.
 
Messages
43,650
Location
'Stralia
It's not so much a spec FOR multigrade, was probably a spec AGAINST rubbish VII in the past. Speccing straight weights made eliminating problems quite a bit easier.
 
Messages
8,711
Location
Nothern USA
Since lawnmowers seldom are started in cold weather, the engineers may have seen little need for introducing multigrades in the past. If I had a lawnmower taking oil, I wouldn't want to mess around keeping a straight oil around just for it.
 
Messages
6,318
Location
Canton, GA
I dont think it matters what you use as long as it`s changed when it should be.Now of course I wouldn`t use a 20 weight oil.I will mention my new Toro 6.75hp B&S was a little noisy on GC,I put in Pennzoil HD-30 and no more noise.This is the only engine that I have had to do this.
 
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Messages
39,781
Location
Great Lakes
 Originally Posted By: Quattro Pete
 Originally Posted By: 1999nick
For several years the number one recommendation of Briggs & Stratton has been synthetic 5W30 motor oil. [...] B&S says that use of nonsynthetic multigrades in their engines might result in excessive consumption in very hot temperatures. They recommend 5W30 synthetic for temperatures from -20 to +120.
Interesting. I recently asked Toro about the oil for my new mower (B&S engine), and they stuck by the owner's manual regurgitating that I should follow the recommendation which came from B&S - it says to use straight 30-weight and nothing else.
But then again, that's just what Toro says. However, the B&S engine manual clearly allows for other weights depending on temperature, just as you pointed out. I just re-read the B&S documentation, and here it is:
 
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