mainly because I want the ability to tune the motor down the road. Its a B18C1 and bolt-ons are almost done. I eventually want to upgrade the topend (no pun intended) with pretty much skunk2 stage one stuff and for the bottom rods and like 11.1 compression pistons at the most. I only have access to 91 octane and thats the compression type-s' run so i figure it would be safe in the mile high zone. So wouldn't i have to have a tune program to get it running right and making the most power? They say you can't tune obd-2 ecu's really well so thats why. What do you think?