Isx 870 with 1.2 million miles 05 international

[Izzyrod52]

My dad owned it from late 2010 to late 2018. I started driving it in 2013 and I bought it in march 2019. It was at a dealership we traded it into for a few months but no engine work. I've been the one doing all maintenance and driving since mid 2014. I've never tried dropping a hole and running 55-60 because I always thought under 15 was the sweet spot. I wasnt aware I needed to be over 15. That's something I could definitely test and see how fuel mileage looks. Usually at 63-65 1375-1400 I see 6.5 on average. Truck is an ex wal mart and always heard bad things but ours was always a solid money maker. Even to this day I'm barely looking into major engine work. My dad bought it at 675 or so and we've just about doubled that with no major work done. Just a clutch and a rear end in 10 years. And good maintenance of course. But no secret formula, just maintenance and making money. I couldn't be happier which is why I'm willing to rebuild and stand behind it 100 %