Well the question is not between synthetic oils and regular oil, it's about when should the oil be changed.....both Royal Purple and Mobil 1 websites recommend following the manufacturer's recommendation, in this case, every 5,000 miles or 6 months, WHICHEVER COMES FIRST !!!! So I'm sticking to my guns and say it should have been changed on or around July 14th.

 

So what about new cars that sit on dealer lots for 6 plus months and don't have the oil changed for another 5k miles or 6 months after it was purchased.

 

Any vehicle that just sits is subject to moisture and condensation build up. Even junkyard tranny's that sit for a while get condensation in them , so they are risky. Most times after I buy a car, the first thing I do is change the oil. My Ranger was an exception as the oil was just changed before I got it, it looked fresh too. However I did decide to change it to Mobile 1 at the first oil change time.(6 months)

I doubt that the sky will fall or you'll get any noticeable problems, so it's a 50/50 thing.....If it were MY truck, I would change it at the six month time, and not pay much attention to the mileage numbers, as I too have a very low mileage per year.

 

Of course they recommend following the manufactures recommendations, think about their liability if they didn't. UOA's will tell you the real story. You should poke around BITOG...


http://theoildrop.server101.com/foru...eads.php?Cat=0

 

So who would know the engine better than the people who designed and built it ??

The engineers at Ford or some Goober on the internet ??

 

I'm not sure that I understand your response, who is the goober? The engineers at Ford base their recommendation on "average" oil. Some people will use the cheapest oil available, some will use the best they can find - so split the difference. If the manual tells me that I can go 5000 miles on dino, I can surely do it with synthetic. Why would a lube manufacture tell you to disregard your owners manual, they would be accepting a huge liability. The Mobil 1 Extended Performance line is "Guaranteed performance and protection for up to 15,000 miles." That sure tells me something.

 

You're missing the point, the point is you can go 5,000 or SIX MONTHS, WHICHEVER COMES FIRST. Once that six month time limit is up, it's recommended to change the oil regardless of how many miles you've put on.

There's also other factors involved. Is the vehicle under warranty ?? Is the engine clean or dirty ?? Extreme driving conditions ??

 

I hear what you're saying. My point is there have been plenty of UOA's (used oil analysis) that have proved particular oils are still fine well past the 5k/6 month window. One of the benefits to using top quality synthetic oils is the ability to extend your oil change interval - even though I still drain mine at 5000 miles.

 

Better safe than sorry, I'll change mine every six months or 5,000 miles whichever comes first.

On YOUR truck, do what ever you want.