OT Oil Life Index

firebrick43 wrote: Brian Jasper co. Ia wrote:  You might want to give some thought to suspension and additive packages... I did, and once again if this was 1985 I might agree with you on 3000 mile oil changes, but oil and engines has gotten a lot better. SM and CF-4 oils have excellent additive packages now, that don't crap out at 3000 miles. Semi synthetics don't do any better in this area, they are only more consitant molecule size and slightly better lubricating properties(slicker/more load carrying capacity) for increased fuel economy and decreased wear at start/warm up.  Have you been in an oil lab?  Seen oil testing?  Seen Oil test engines?  I have to walk but 150 feet each day to.  I agree that 10-12 thousand miles in light vehicles with low capacity oil pans with out extra filtration is to much but there is not reason that 5000-7000 miles can not be used today in average driving, using your head to adjust to sever conditions to adjust your interval.

And have you had to change cam phasers in 3.5L and 5.4L Fords where the owner has been doing the 5K to 7K mileage? 100+ gallon oil sump must be on something like a locomotive. You're trying to compare apples to oranges...