Paccar mx 13 dpf delete | Heavy Equipment Forums. Heavyequipmentforums.com I've not heard of many horror stories on the Paccar engines. But, if you are unfortunate enough to own an International Maxxforce 13, a delete might be the only way to ever get it to run right. It does put folks in a tight spot. But, I don't do deletes. Not worth the risk. RE: Paccar MX-13 tuning The 485, 500 or 510 is the way to go in my opinion. 16.5:1 compression vs 17.5:1 for the lower ratings. I think the lower compression of these things is the reason they're not having head gasket, cracked head, liner, counter bore and fretting issues like Cummins.