Originally Posted By: HKPolice
I think this is a bigger issue than most people realize because most people don't know what to look for. The early symptoms are hard to notice for 90% of the population who aren't car enthusiasts. Serious drive-ability issues probably won't manifest itself until after the warranty has expired.
My Mazdaspeed 3 has 149,000 miles on it. I run Mobil 1 5W-30, initially using a 5,000 mile OCI. Att 83,000 miles I extended the OCI to 7,500 miles. I've had a UOA performed at every oil change since 10,000 miles and fuel dilution has never been even a minor issue.
With a Mazdaspeed CAI and a mild Hypertech tune the car is making a bit over 300 hp at the crank- along with @320 lb-ft of torque. Driveability is excellent and fuel economy averages 27 mpg or better.
I must not be a car enthusiast, as I haven't noticed the slightest problem...