0W30, 5W30 , 10W30 they are all lubricating like a 30 oil, the only difference is the lower number is capabe of flowing better in colder temps. FLOWING CAPABILITIES is the key in the first number

 

The service manual recommends 10W-30 for normal use, 5W-30 for extreme cold and 10W-30 or 20W-40 for where it gets hot. 20W-40 is not an oil I've seen on the store shelves so I've never used it. I have used 10W-40 in the summer.

 

So why not just run 0w 30 all year round?

 

I'm not a spokesperson for Mitsubishi but I'd suggest their recommendation of 20W-40 gives some insight into their thinking. These multiweight oils have liquid plastic added to them. This stuff is known as viscosity indexer. To obtain a wider range of viscosities you add more plastic. So, you are buying less oil and more viscosity indexer. It seems the engineers at Mitsubishi are not too hot on us owners going too far in that direction.

 

Righ You got it

 

I cast another vote for Amsoil 5W-30. Though, running it for 25K mi is not wise for any EVO; The stress thru the turbo, and constant push our cars are put thru demands more frequent changes. The regular oil filter will not last you 25K mi either, so I change it every 5000.
As far as Mobil 1, I can only speak for myself, and the fact that after 5000 I noticed how dirty this oil was compared to the Amsoil.

 

EVOm BS never ceases to amaze me

I will use M1 untill rebuild and plan to push it past 200k also.

120k on M1 10-30 and EP when it available. Changed every 3k. 35r car stock block pushed to 8k rpm regularly. Proper maintenence, proper tune, go a long way.

 

you are right, and that is exacly why i have said over and over that on modified cars a good drain interval can be designated by going through a couple oi analysis labs why because it will help you set a baseline of how if your oil behaving, oil analyis will give you a report and tell you how much more they reccomend you taking your oil drain intervals to.

25k for your DD like you wife camry or Ford Explorer, if you haul anything that will be considered severe driving and interval drops to 17k, this does not apply for modified cars running hard only applies for people with regular cars and most of us own those types of cars, AMSOIL has millions of AMERICANS runing these oil at those levels with no issues at all.

a good default drain interval can be 4-5k