How many miles before switching to syn. motor oil

[upsguy]

In my gassers I switched to synthetic motor oil somewhere between 15k and 20k. Is this about right for a diesel motor too?

[Tough Guy]

With the new vehicles I have purchased, the last being the Jeep with the 2.8L Diesel I used Rotella 5w-40 sythetic after the first oil change.

Chris

[JoeyD]

I waited until 5000 miles on my Express.

[Kennedy]

As soon as it is "economically practical" is the approach that I use. It is absolutely safe to use synthetics from day one. The key here is that I change my oil early and often (dump out the floating trash etc) when new so synthetic price tells me to wait. If I were looking for the absolute best w/o regard for cost or wastefulness, or I planned on running long drain intervals from day one, I'd go synthetic...

[cndnls]

I have a 02 d-max with 184,000 miles on could I switch to synthetic?

[MikeC]

I drove my '05 roughly 1000 miles and changed the engine oil and rear diff. The amount of metal on the magnet in the diff was quite impressive.

I then changed the oil and diff again at 5000 miles. This time going with 5w-40 Rotella synthetic in the engine. About 1000 of the total miles were towing our camper.

At the same time I also flushed the trans with 100% Transynd since no one could tell me if GM ponied up the $$'s to put any in at all at the factory.

I figure some $$'s now can save me some headache and $$'s later.

Mike

[WILLYD-MAX]

cndnls
I don't think there is anything wrong with switching a high milage vehicle to synthetic. Synthetic oil is generally a cleaner running oil so on a high milage truck it would'nt hurt to change the filter again at say 3k because of the oil cleaning up some of the deposits in your engine. Just my 2cts.

[cndnls]

Thanks for the info! I have been debating on changing this brings me alittle closer to an answer.:confused:

[mark45678]

you can use syn oil from day one if you want , just dont forget the most important oil changes are the first two or three . I do 3 oil changes in 5000 miles then I use the GM drain schedual. The cost is the only reason I dont use syn oil all the time.