Typically SAE 30 only is recommended, use of multi grade oils such as 10W-40 voids warranty.
2006-06-25 05:24:18 · 4 answers · asked by Truth be Told 3 in Home & Garden ➔ Do It Yourself (DIY)
Multi viscosity oils have alot of volume index improvers and pour point depressants to meet that 10 or 5w-30 oil (5 in the cold, w stands for winter, the last number is its viscosity at operating temp) and in a air cooled engine, which runs ALOT hotter then a cars engine, that oil will be sheared in no time. Straight weights have no VII or PPD's, so they will not shear.....but of course they get thicker as it gets colder.... so more wear.
Synthetic multi weights contain very tough and natural PPD's and VII's...... they are now being recommended because of this. Heck, mobil 1 or amsoils 10w-30..... are actually straight 30 weights.... but flow like a 10
Using 10w-40 will void the warranty due to it being a 40 weight at operating temp......
2006-06-25 18:15:28 · answer #1 · answered by 572ci. 5 · 3⤊ 1⤋
Because lawn mower engines do not heat up fast enough and it is too thick and makes the engine work extremely hard.
2006-06-25 05:55:26 · answer #2 · answered by snowqueen_icefairy 2 · 0⤊ 1⤋
Because the lawn mower Engine is to small,and it's to thick and heavy
2006-06-25 06:22:26 · answer #3 · answered by Anonymous · 0⤊ 1⤋
use 2 cylinder oil.
2006-06-25 11:14:44 · answer #4 · answered by Jenny w 1 · 0⤊ 1⤋