Castrol Syntec

Hey, does anyone know anything about the amount of time one can go between oil changes with Castrol Syntec? My boss owns a 97 Ford F-150 with approx 175,000 K on it and Syntec is all he has ever used. He says that you can go approx 8,000 miles between oil changes with it and went further to say that this was written right on the bottle.

Well needless to say, I put some syntec in my Pathy, but did not see any recommended oil change mileage on the bottle. 8,000 miles seems like an awful lot to me. 6,000 miles even seems to be too much to risk. But if this is not the case, How do they justify charging almost $5 a quart for the stuff. If I have to change it every 3,000 miles like normal, there is no way that I will ever buy the stuff again.
Anybody know anything?

Demps.

Just my own opinion, but I wouldnt go any more than 5000 mi. between oil changes. If you tow with it, the synthetic oil is a good choice because the viscosity does'nt break down as quickly as conventional oil. But, the oil still gets dirt and carbon deposits in it so no matter what, stay with the 3-5000 mi change interval. Just my 2cents worth.

Thanks for the info Mr B.

This at least gives me something to go on. My old boss was a cabinet maker, so he was towing a trailer frequently between jobs. Still don't know where he got the 8,000 mile number. I guess your 3-5K number supposes that it is ok to go over a couple thousand miles with this oil.
This makes me feel a little better, as long as it dosen't wreck anything.

Thanks again,

Demps

Synthetics are capable of going up to 25,000 miles. Check the AMSOIL site. They Guarantee theres up to 25k. I have used Syntec and Mobil1 - I change oil once a year.I also use high performance filter(X2).