What oil for 07 foreman 10w-30 or 10w-40

10W-40 has too much VI improvers and thats no good, especially in motorcycle applications where the oil is subject to heavy shear. Too much VI improvers also creates problems with gumming up the piston rings. There are numerous articles on this and i dont know why bike manufacturers still recomend this grade. 10W-30 is a better choice here. I personally use shell 15W-40 Rotella T which is a heavy duty diesel engine oil also approved for gas engines. It is extra shear stabil and VI improvers are kept in ratio so it is good for bike engines. Many people use it in motorcycles and have great results.
If you are going to use a 10W40 grade, make sure it is synthetic oil, as you get away from the VI improvers.

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I looked in the owners manual and it calls for 10w-30. Some people have said to run 10w-40 in it. I"m going to do wha the manual says and run 10w-30.

Amsoil 0W-40

Another vote for AMSOIL 0W-40 ATV oil.

in the winter i use 10-30 but in the summer i run 20-50

up until 06 honda used 10-40 in almost everything. Now in 07 they changed to 10-30 so that the 07 models years are supposed to have 10-30.