I am a very firm believer in synthetic oil. I have used it in all my cars that I have ever owned. When I bought this CTD I have been asking around and looking for a synthetic 15-40 and everyone tells me I am crazy use standard 15-40 synthetic not required. Well I am sure that it isn't required but I am selling a 97 dakota that has over a quarter of a million miles on the original trans and engine and I thank synthetic oil for most of that. (consistant maintenance for the rest). So what is it...is there not a synthetic 15-40 available or should I tell the people telling me that that they are crazy. And is anyone else running synthetic in their diesel motors and what brand? Also going to flush the trans and put Amsoil in it, along with a deeper pan for better cooling.

Thanks for all the help I have already received. I am a new member and already I am hooked. It is the first thing I do in the morning and the last thing I do at night is log onto the site.

 

There are a few 15-40 synths out there. I personally use amsoil 15-40 full synth. and their bypass oil filter system. A lot of guys on the forum do the same . look at some of the posts about amsoil.
GO WITH THE SYNTHETIC!

 

I am a firn believer in Amsoil. My truck has it from front to back. Nothin's better!!

 

My rep. says not to bother w/ the by-pass system because it is cheaper to just change the oil every 25000 than to go to the expense of the by-pass and change both filters and have the test done. If you need more info PM or email me.

 

25000 miles???? Holy @#$&. What is the cost on the amsoil per quart?

 

Dont' forget Royal Purple which is another high dollar synthetic oil. That's the line of oils I'll be using after I get at least 10-12,000 miles.

Royal Purple is about $6 a quart, and I think Amsoil is a little bit more, but could be wrong.

 

Just a suggestion but it is probably easier to find a 5W40 or 0W40 oil than it is to find a 15W40 and it may even be cheaper. It will also provide as good protection at higher temps but substantially better protection on cold starts (even in summer) which is where most engine wear occurs. I personally run Esso XD3 0W40 all year round in mine, Mobil 1 delvac is another popular oil (5W40) and easily found in stores such as Walmart. Any oil question? A good site is www.bobistheoilguy.com

 

how many miles can you go between oil changes when using synthetic oil

 

If you do oil analysis then probably roughly double, myself...I still dump at the normal interval as oil is cheap and I don't have time to deal with oil analysis (not that it's not a good idea). some still recommend that if you use extended intervals to change the filter at the recommended normal interval.

 

i too am running 0w40 XD-3.. it seems to be a good oil it is pao [base 4] basestock on it.. in canada it is under the esso name. in the usa i believe it would be under the exxon name...

 

AMSOIL 15w-40 is available & they make a 0W-30 also just for diesel engines.
I myself don't change my oil, just the filter and by-pass when required. I do have an AMSOIL Tri-Gard By-Pass system installed. I just send in a sample every 7.5k miles or 6 months. THen wait for the results and change the filter if necessary. I currently have 24k miles with just 2 filter and 1 By-Pass filter change.
Just my vote and one man's opinion

 

15w-40 synthetics are made by Amsoil, Redline, and Royal Purple.

That said, there's no reason to use a 15-40 with synthetic. Far better to have 0-40 or 5-40, as others have mentioned.

BTW-- Amsoil's 30W diesel oil is 5w-30, not 0w-30.

Personally, I think the only people who should be running a 15w-40 are those who tow very heavy (max gcwr+) in very hot climates. All the rest of us would be better off with e 30W- class lube.


Use Redline 10w-30 and Rotella 10W30, both with good results. Since the 6.0 PSD specs 10w-30, there are going to be more good oils available in that spec, and I'd encourage EVERYONE to strongly consider the ligher oil.

Rotella 10w-30 has a pour point of -40°F!! That's as good as most synthetics.


I also love synthetic oils, but an honest person will admit that dino oil formulations have made MUCH progress relative to synthetic formulations, and the performance margin that synthetics enjoy is getting slimmer all the time.

 

i pay 60.00 bucks for a 12qt case of amsoil 15w-40 synthetic oil delivered to my house. that's cheaper for me than going to wallyworld and buying mobil 1 truck and suv oil off the shelf!

 

I agree with the statement about mainataining service intervals even with synthetic oil. To me, the biggest advantage of synthetic over dyno is the cold starts. I change my oil not more than 5000 miles apart so just stick with Rotella-T but prefer synthetics in the cold weather.

 

I defintily agree about the price of Mobil1 being expensive. As I said before I run Esso XD-3 0W40 and it works out to be about $4 a Litre more than Rotella T (15W40 non synthetic). The last case of 4-4L jugs came out to roughly $70, bought from the local Exxon/Esso supplier in town. Kinda hard to not justify the increased value for so little money. I personally would not run a 30W oil (5W30, 10W30, etc) for warranty issues. If something happened DC could have a reason to deny warranty. If you look in the owners manual at the recommended oil viscosities it shows a chart. As long as the viscosity is as good or better than the areas in the arrows you are OK. If it isn't... I don't really understand why you wouldn't want to consider running a 40W? It really won't save any fuel mileage? It could cause more wear in higher operating temps (even if you don't tow) so in the case of my expensive truck I choose to run the equivalent or better of the minimun oil viscosity recommended by both Dodge and Cummins regardless of brand. Hust trying to let everyone else see there are other more affordable/easlily obtainable options for those wanting to run synthetic oil.

Super Gewl, thanks for the info on bypass systems, very informative and good to know.