10w or 15w?

[RugbyPete]

I'm going with castrol gtx next, after good feedback.

What weight should i get? I was going to go for 10w40 after getting bad economy on 5w30 (why, i never found out)
but recently read that 15w40 would be better, as the oil is less stretched between 15 and 40, opposed to 10 to 40 that has to work harder to hit each grade

What say you, 15w or 10w? bearing in mind the recommended is 10w-40 for my car

Also, castrol high milage is supposed to be 'thicker' whatever that means in real terms. now i've hit 100k should i look to this?

ta

 

[RugbyPete]

my cars a mitsubishi galant v6 24v 2.5 by the way

 

[ConfederateTyrant]

Go with 10w-40, it'll be easier to crank than the 15w40. A synthetic 5w-40 would be the best choice if you can find it for cheap.

 

[simple_gifts]

Not sure why you would move to a heavier oil after getting poor economy; weight of oil is that last place I would look into getting better mileage, and generally people move to thinner oils, not thicker to get a mileage benefit.

Welcome BTW.

 

[RugbyPete]

i dunno either. i could onl;y presume my cars ---- at pumping the low weight... it takes a while for the tapping noise to die down (common on the G's)

 

[pp_rp]

Quote:

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Not sure why you would move to a heavier oil after getting poor economy; weight of oil is that last place I would look into getting better mileage, and generally people move to thinner oils, not thicker to get a mileage benefit.

Welcome BTW.

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This is good advise.