I have a lawn mower for which SAE30/10W30 engine oil is recommended. I use fully synthetic 5W30 engine oil for my cars and once the lawn mower has been running after a couple of hours of running I'd like to change to 5W30 - if I understand the only difference is the start up will be easier (oil thinner). Will it then be OK to use 5W30?
5W30 instead of 10W30 for a 4 stroke
- Thread starter aaronjthompson
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Yes
I run 5w30 Royal Purple HMX in our Craftsman 17.5 hp lawn tractor.
I run 5w30 Royal Purple HMX in our Craftsman 17.5 hp lawn tractor.
You'll be fine, even Briggs themselves sells a 5W30 for lawnmowers now.
Why bother with a VII for a lawnmower engine? Use a SAE 30 monograde for the longest engine life and least smoke.
But only if it is full synthetic.
Well yeah, the OP said that they're using full syn, based on their previous posts, I'd assume it's Mobil1 ESP 5W30 that they intend to use, I assume that should be a fine oil in this application.
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I'm [not] sorry to burst a few bubbles in here, but I use a buddy's Kawasaki FR series that sees double duty (2 large properties regularly, mine and his). No hour meter, but it's schedule since new puts it somewhere around 1500-1800 hours. It has only seen 5W-30 full synthetic since the 8 hour factory fill dump. We've never needed to use the choke, never had to top-up the oil (it stays at the full mark), and it has never given a single puff of smoke. It literally still runs like brand new. I can vouch for all of this because my buddy won't touch the engine and I've done all of the maintenance since new. If I didn't do it, he'd be some dealer's best service customer.
"Longest engine life"
"Least smoke"
"Expect more oil usage"
Ha! If these are true, I should definitely see evidence proving these statements at 1500+ hours. But I don't.
OP, use the synthetic 5W-30 and never look back.
"Longest engine life"
"Least smoke"
"Expect more oil usage"
Ha! If these are true, I should definitely see evidence proving these statements at 1500+ hours. But I don't.
OP, use the synthetic 5W-30 and never look back.
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If Perth, Australia, has a hot climate and your engine is air cooled then I believe I'd use a monograde SAE 30. Most manufacturers recommend against 5W-30 in hot climates (with the exception of Briggs apparently). I would personally save the 5W-30 for the next oil change on the car.
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I never had to add any oil
I can't believe this is the 1st suggestion for a 40 grade, but I use and suggest 0w40 and 5w40 in all OPE especially in hot climates. If your goal is to consolidate to a single grade, the 5w30 would work fine. I haven't seen consumption issues with 30 or 40 in OPE.
There is a reason why the preferred viscosity for these small engines is a SAE 30 monograde. The base oil in a SAE monograde is almost twice as thick as that of a 5W-30 and protects against wear much, much better as a result. There is no viscosity-index improver (VII) plastic in it; so, you won't be damaging your lungs by inhaling burned plastic while mowing your lawn. It will leave less deposits in the engine as well. Conventional oils tend to burn cleaner than synthetic oils, and again your lungs will thank you.
These days there is not much difference between a conventional 5W-30 and a synthetic 5W-30. However, neither will perform nearly as good as a SAE 30 monograde. Use the ideal oil for these engines, which is a SAE 30 monograde. If you can find a SAE 30 monograde API CK-4 HDEO, it's even better with yet a thicker base oil and a more potent and versatile additive package.
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The B&S 6.25hp on my mower has consumed thinner oils since it was new. I started out with 5W-30 after a few hours on the "break-in" oil, and it consumed. I moved it up to Mobil1 15W-50 and it goes all summer without moving much below the Full line. Not sure why you'd want to run a thinner oil in an air-cooled engine in a hot climate.
It's good to know that the HTHS of a quality straight 30 is 3.8. In other words, it's far more robust than the 3.0 or lower HTHS of a 5-30 under the hot conditions an air cooled engine experiences.
Synthetic 5W-30 is at a significantly lower viscosity at 150c vs. straight 30 mineral oil.
It's only the same at 100c.
I lost 2 water pump engines due to oil related failure, using 5W-30. My neighbors lost many generators after the hurricanes. Hard working air cooled engines really do need a more robust oil.
Just an FYI, my Kawasaki powered push mower's normal oil temperature is 131c during a summer mow.
Synthetic 5W-30 is at a significantly lower viscosity at 150c vs. straight 30 mineral oil.
It's only the same at 100c.
I lost 2 water pump engines due to oil related failure, using 5W-30. My neighbors lost many generators after the hurricanes. Hard working air cooled engines really do need a more robust oil.
Just an FYI, my Kawasaki powered push mower's normal oil temperature is 131c during a summer mow.
IF the OP is using Mobil1 ESP 5W30 that's not much of a problem it's not your standard ILSAC 5w30 oil you find commonly here in the US that's geared towards fuel economy, it's got an HTHS viscosity of 3.5.
Will do just fine... Briggs and Stratton actually recommends 5w30 synthetic
This!
If it must be 5w30....opt for ACEA specs....but pay attention to avoid our "CAFE" ones! (C1/C2/A5/B5/C5)
EUro in 5w30 with high HTHS is usually coupled with C3 + VW 504/507 / MB 229.51 / BMW LL-04....
On your market that would "translate" into....Mobil1 5w30 ESP or Shell/Pennzoil Euro LX
Where im at there is 2 types of 5w30. A5B5 stuff which is resource conserving and thinner than A3B3/B4 which is thicker. Between the two its 100c cst 9.9 vs 11.5ish. hths is also different between the two.
Dunno which is safe to run in lawn mower but sae30 here is around 11 cst at 100c
Dunno which is safe to run in lawn mower but sae30 here is around 11 cst at 100c
I run 10w30 Rotella T5 in my 20 HP B&S engine. This is a very stout blend oil and it works well in Florida. Ed