[tholt846]

Has anyone noticed a different in fuel mileage like some guys say with 6.0s? if ya switch to synthetic could you run your intervals a little longer on the oil change?

 

[gtspowerstroke]

you can definatly run longer intervels. Biggest thing with synthetic is keeping it filtered. It doesn't brake down like dino oil does. With a bypass filter I've heard of guys running 100K on an oil change.

 

[USAFdieselman]

100k??........The filter wouldn't last that long.

 

[PowerChoker32]

I run Amsoil 15w40 synthetic oil with a Amsoil absolute efficiency oil filter in my truck. I was told by Amsoil that with that oil and filter there is a 25,000 mile/1 year oil change intervals. They also conducted a test on big rigs that ran 60,000 miles over the road and had a oil sample sent out to the lab. The lab test showed that the oil was good for another 30,000 miles no problem. They are running Dual bypass filters and change the filters every 30,000 miles but using the same oil. Just goes to show you that the stuff does work and is worth the money. 100 dollar oil change, and no crawlin under the truck in the winter out in the cold. Once a year and check it normally for any burn-off.

 

[gtspowerstroke]

100k??........The filter wouldn't last that long.

I guess I figured it'd be obvious that you would change the filter a little more often. I don't recall the exact intervels but the full flow filter you change more often and I think the bypass filter you change like every 25K. Have oil analysis done when ever you change the filter to make sure the oil is still good and run it until the oil sample comes back bad. The synthetics don't brake down like dino oil so they last a long time. You just have to get all the junk out thus the bypass filter which filters down to like 1 micron or something like that.

 

[Cummins_Beast]

I'm afraid to even try synthetic in my PSD with 195K miles, would probably leak like crazy...lol

 

[gtspowerstroke]

Hard saying. Synthetic molocules are smaller so they will seep through gaskets easier. That's why people seem to think it will start leaking. That's also the reason they lubricate better. They get into the pours of the metal better.

 

[BillsFan]

I'm afraid to even try synthetic in my PSD with 195K miles, would probably leak like crazy...lol

I was told not to run synthetic in high mileage vehicles because it tends to clean out some of the gunk conventional oil leaves behind that may be plugging a leak.

Despite the warning I started using it in my 02 with 120k miles and have had no problems. I think it likes it!

 

[worm drowner]

I switched to synthetic in my 96 at around 120k. So far at 145k, it's fine, leakwise.

 

[Pocket]

The synthetic leak myth just won't die. Back in the old days synthetics would cause gaskets to shrink and you'd end up with oil leaks. Today's synthetics don't do this.