I have a new 06 CTD 2100 miles when could you change to synthetic oil at the first oil change or should I wait until a certain mileage?

 

I waited till 15k.I changed factory fill at 3k then next at 5k etc.Until 15k then went syn.

 

Some say 15,000-20,000 miles before changing to synthetic engine oil. I think alot depends on operating conditions.

If you tow alot or heavy then 5,000 miles would be o.k.
If you live where it gets below freezing frequently or months on end then change the oil when it gets to those conditions.

The worst that could happen is it takes the engine longer to break-in.

In my opinion with the quality mineral based oils available now days I wouldn't use synthetic due to their cost unless it was for extreme cold conditions.

 

Thank you for the responses I will most likely wait until I have towed something or 15K before making the switch.

 

WOW, every 2k you must have some $. Seems like over kill to me.

 

I changed mine at the first oil change and haven't looked back since.

 

Wow.No ran the next 5k etc.till 15k

 

This is the exact advice I would give as well. I see no real benefit to using synthetic, other then the cold flow properties. I do use a synthetic 0w40 in the winter, but switch back to a conventional 15w40 during the summer. I take an oil analysis every oil change, and I haven’t seen a significant difference between synthetic and conventional oil. As I take more samples I might start seeing a trend, but as it is now, I really don’t see much difference.

 

Interesting.
Have you seen any mpg differences, particularly on tanks just before and after the switch? (Winter mileage is probably lower for reason other than oil)

 

I was reading about motor oil on Wikipedia.org the other day. It mentioned that any multigrade oil has some syntheitc part to it, long chain polymers that change with the temperature which changes the oil's viscosity. I never knew that!

So really I guess when I use a synthetic motor oil really I'm using an oil that is more synthetic (i.e. 100%) than regular multigrade "normal" motor oil, which may have a high amount of synthetic oil in in anyway.