3.0 Diesel long term K&N CAI + muffler delete observations
After 5 months or so of running the K&N CAI and muffler delete on the 3.0 diesel I can say that there are definite performance pluses. They are not apparent for city driving...For whatever reason this engine strategy doesn't do a good job of optimizing air & fuel when you allow for more air in/out during part throttle city driving. Prolly lost a little low rpm part throttle grunt and 1mpg during city driving. Mashing on it to WOT for passing, off-roading, high speed highway, or spirited driving is where higher air in in/out can be felt and measured. Easy seat of the pants improvement on WOT or rolling passing conditions. I just ran Memphis-Chattanooga-Atlanta-Charlotte-Raleigh-Nashville-Memphis over to past week and drove 75-80 mph and got 28 mpg. Before the K&N/muffler perf mod, 80 mph highway cruising had me at 25-26 mpg.
Going around Chattanooga and in hills of NC have some pretty long, steep grades and the JGC ate that shit up. Those steep twisty roads had speed limited to 65mph; when I had to slow for other vehicles then re-engaged the cruise control, it shifted down and throttled up and had back on the set point very quickly; almost by the time I was passing the other vehicle.
Every day brings a new battle with technology.