wood_n_soldier

Can anyone give me specifics about the type of Synthetic oil you use and do you know if they are good for year round or should just be used when it is cold out. I normally use premium blue 15w-40 motor oil and everything else (i.e. the transmission, power steering...) has the original type of oil/lube. I have been thinking about switching to synthetics but don’t know much about them.

Mexstan

Suggest that you add a signature with your truck info so that the folks can give you advice more suited to your specific vehicle.

BarryG

You will get a variety of opinions on synthetic and brands. Hopefully all will remain civil on such a seemingly simple question. I "personally" use Amsoil front to rear but that is just my choice of brand there are other synthetics and dino oils that are quite good. Synthetics do cost more but do provide superior protection at least in some aspects. There is also the true synthetics verses blends. Many of the labeled synthetics are blends but have enough syn in them to be called syn and not a blend. I think for it to be a true syn it must be a class IV oil(someone please correct if that is wrong). The rub comes in with do you really need the extra protection. Many if not most people run dino oil for hundreds of thousands of miles with no problems at all. Synthetics are great for year round use. If you live in a very cold climate I would recommend using syn. Below is a lsit of what I use. I run a bypass oil system so I run somewhat extended drain intervals with my synthetic. In the warm months I run Amsoil HD Diesel 15w-40 for the engine and in the cold months Amsoil Series 3000 5w-30 (I prefer the thicker stuff in the summer time for the high heat of the desert that I seem to be in so much during the summer and prefer the thinner in the winter but either one would work year round). Works for me as I change my oil twice a year (though filters are changed more frequently) at approx 15k per oil change. In my transfer case and auto transmission I run Amsoil Synthetic Universal ATF, In the front and rear diffs I run Amsoil series 2000 75w-140. In the power steering pump I run Valvoline synthetic power steering fluid it seemed to cut down on the cold temp growl I had. I would do as much research as you feel is warranted and then make your decision on brand and whether syn or dino. You will probably get many many differeing opinions on this one.

By the way welcome aboard. This place has tons of info you might try a search on oil here and you will likely get hours of reading.

Johnny

After the break-in period I switched to Amsoil HD 15-40 with the bypass filter system. Every three months I send an oil sample in for testing. Every time it has come back that the oil is safe for continued use. I change the regular filter twice a year and the bypass filter once a year. The oil now has about 50,000 miles on it and it's still good. I also have synthetic in the differential with a larger capacity cover. We tow a 7500lb fifth wheel trailer and have never had a problem with lubrication. Hope this helps. Our truck is a 2001 QuadCab 2500 Diesel.

ammo5797

I have been running dino oil (Rotella 15W40) forever in my trucks and have just now switched my CTD to Amsoil (15W40). I noticed the truck started and idled at a lot lower noise level in the cold and my oil pressure picks up faster and stays in a more normal range when cold than before. The motor seems a lot happier when cold with the syn. I haven't switched anything else yet, but I'm happy with the syn so far. My2c~

wood_n_soldier

OK so it looks like the general opinion is syn's are a better, Are there any concerns I should be aware of about switching? special filters? - - or I've been told once you switch to syn's you should not switch back any truth to that?

Dieseldude4x4

Even though I am an AMSOIL dealer, I would not totally agree that synthetics are better. There are lots of cases where the trucks have hundreds of thousands of miles with regularly scheduled dino oil changes and proper maintenance. I run synthetic in my truck but I run regular stuff in my cars.
If you are going to use synthetics, then you should use the filters designed for that oil to get the best performance out of the oil.