:shakehead: I don't get it either. When you trust a guy enough to let him wrench on your truck, but not enough to listen to him about your filters, WTH? I think this experience is a real eye opener to him. Expensive, too. Sometimes, the only way to reach a guy is through his wallet... ...

I bet I can throw that filter away, now!! He thinks his great mileage is due to it, but I mentioned to him, "What did you save? You're gonna have over 10 times what the filters and mileage paid off in repairs!!" He got quiet then changed the subject..... It's hard to argue with the pieces right there in front of you.
Curiously, I want to run the numbers..... let's see, maybe 2mpg gain? 4mpg gain? Soooo, even at current prices, say $3. 68gal, getting 20mph costs you $0. 184 a mile. At 22mpg that goes to $. 167, and 24mpg, it's $. 153... ... so $. 017 and $. 031 gain,
if you gain 4mpg... ..... At what? $45 a K&N Filter? It takes 1451. 61 miles to pay for the filter, then you're making money!!! OH, wait, let's figure engine repairs, first... . The engine will run... what, 400k average miles? Usually the trucks get worn out around then if you work them offroad pretty hard..... lets use that number 400k, as it's double what this engine has made it..... so at 200k the engine goes down... . That's gonna be around $3000 to rebuild if you catch it quick..... or at least what I'm gonna charge to pull it, get it bored, sleeved, new bearings, piston, wristpin, etc... . Well, the first 96,7774. 19 miles after it paid for the filter are used to pay for the new engine in another 100k.
Ok, let's look at this at another direction. So if you ran the stock filter, and average 20mpg over the life of the truck, which is a high average, I know, you have paid $73,600 to get to 400k miles on the truck. So, by comparison, if you ran 400k using the K&N and had to rebuild the engine, let's look:
at 22mpg, that's $66,909 + $3000 to rebuild engine, and time down.
at 24mpg, that's $61333. 32 + $3000 for engine and time down.
Well, those numbers don't look TOO bad. But then, what if you don't have an awesome mechanic like my customer does that can rebuild it so cheap? That's gonna cost you closer to $6000 for a reman'd engine, + installation..... so close to $7,500. With that number, you lose money at 2mpg, but a short gain at 4, not counting your down time. It's taken me 3 months to get to it. There are others in front of it. And to even CONSIDER making those kinds of mileage gain, you're gonna have to run the truck down the highway at cruise speeds..... so I'm not sure how realistic those numbers really are!! They'd have to definitely be in the top of the spectrum..... both mileage and mpg increase.....
So, in conclusion, the only thing I can really think of is... ... ... ... . I do this too dang cheap!!!
