18:1 is good for maximum power but bad for engine longevity.
20:1 is a good balance more so for power
22:1 is spot on for longevity
24:1 is perfect for constant heavy towing.
16:1 is perfect for putting holes in pistons, more so than that the amount of extra power you make from 18 down to 16 is actually quite small.
is the tuner an experienced petrol tuner just having a crack at tuning diesels for the first time?
