Engines to avoid on F-250?

ib516 wrote:

Crabbypatty wrote:
Ive had K & N cold air kits on 5.7L Tahoe and 8.1L Suburban each sold with over 250,000 miles and going strong. It adds gas mileage and there is a noticeable uptick in power when towing. Tweaking the exhaust and a a 5star tuner, like I used on the Suburban, will increase horsepower more than 5% making towing easier and more fuel efficient. While diesels get better mileage and have more torque, it don't tow anything that heavy to warrant the extra initial price and fuel costs. 95% of the time the truck is used locally, then we tow with it. Very happy with the 6.2L 6 speed setup. The Burb was 3 speed and bruted through towing. This works for us.

Dyno test after dyno test says "cold air" kits from the aftermarket make zero power, and in some cases reduce it. The cotton/gauze filters also pass through a lot more dust. I had a K&N in my 2002 Dodge/Cummins. I found dust in the intake tube after the filter and gunk on the turbo blades. It went in the garbage.

Oh, and BTW, the factory air intakes are also cold air. Anyone who thinks and open filter element under the hood is sucking cold air is being lied to.