Bruno55, I aftermarket tuned my original motor at 33k to turn off EGR to improve longevity & minimize repairs, improve mileage, power, add turbo brake etc. Deleted due to clog at 260k miles but didn’t delete the EGR cooler. On a long cross country TT tow it seems low coolant from leaking EGR cooler caused it to push a head gasket at 371k miles. The emissions systems & governmental AEM detune has been especially hard on these motors.
The replacement motor was fully deleted from day one and has the EGR cooler removed to eliminate that risk. At 420k it’s still going strong. It just had water pump, and cracked valve cover repair and the trucks first turbo replacement. Previously it had a tone or reluctor wheel failure. Friend & fellow transporter has 450k on his. Son had over 200k on the one he drove before leaving employment with that company. SIL has about 90k on his. And I know we have at least two over 300k on the other forum. I believe all deleted not that a tune can fix damage done or unclog oil passages etc. But it is a problems preventer & minimizer and longevity improver IMO.
There are people who’s truck duty cycle works well and lasts even stock never been tuned or AEM detuned. Steve who contracted with the same company I did had 212k on his untouched zero repairs truck when he sold it. But pre AEM days.
As someone living in California, I'm wondering what is the longest without delete/tune (ie totally stock)? I do see trucks at auction with over 200k, but no idea if they were tuned or not.