It won't hurt it at all. I used to run it in a Volvo with 500,000KM. I read somewhere in a forum about a guy using old, recovered diesel oil in his 5.0 F150, said it worked real good. If it caused trouble in the cold because of thickness, then big trucks wouldn't want to run it, right? They have bearings that need protection too, most transport trucks get over 1 million miles on a rebuild.just bought my fiance a 03 Taurus SES Sport with the duratec engine with 125k. so far so great and she loves it. well i done some research here (love the site btw) and i want to change the oil ASAP just cause i dont know when the last time it was done.
Heres the question. Here at my work, we order 15w40 by the drum and its free game. its pure synthetic (Schaeffer Oil | Supreme 7000 15W-40 Synthetic Blend Motor Oil) and we use it in tractors to 4 cylinder chevy colorados. i use it in my personal 04 sierra v8 and my 65 mustang. oil samples get sent back to them on every oil change and mst of the time oil change intervals are around 5-7k. i like this stuff to say the least.
will it do any harm since this is begining to see high miles?
also, changing trans fluid and filter this weekend thanks to this site!
Just my humble opinion. I currently run cheap 10w30 and replace it on time, every time. It only burns 1/4 L of oil every 5k. It's usually fairly clean when I change it, too. I also buy it in 20L buckets, for the savings.