I did the calculations based on fuel in / odometer read. Had an accountant friend of mine confirm my data. (The data from the computer is pretty close though within .5L/100Km.)

I did buy new tires as my truck was also not too happy staying on a straight line. Went with michelin LTX MS2 stock size that were to improve milage as well as sidewall stiffness. (Also stock alignment was horrible! 0 castor one side and 2.5% on the other... went to 4% both sides with 0 toe in... so even alignment with stupid toe in can't account for this. After the engine is fixed I would like to experiment with a little more toe to make things track even straighter.)

Otherwise totally stock.

Thanks for your help.