I just reached 16k and its time again for an oil change.

Is 16k to soon to switch to synthetic? (mobil 1 truck and suv)

I've been on 1 long 3k trip, lots of 300mile trips but have only towed once 75 miles and towed about 4,000 lbs.

I don't notice the engine and mileage any different than when new (17.5 mpg).

 

IMO I would wait until 30K. These engine take a long time to break-in and with only towing once your is still pretty tight. I have read several post saying to wait until break-in is over. The syn. will not cause any problems, just will add additional time until engine breakin is completed. Just my .02 I am sure like most things opion will vary.

 

you never want to use synthetic in an engine that has already been broken in on mineral oils.use it from the start or very early in its life or don't use it at all .Use it like a truck and break in with synthetic is not a problem but once it's broken in you don't want to disturib any of the deposits that exsist that help seal the rings at 16k you can still do it but there is very little economic benefit if any to it and little mechanically if your pulling hard and for the long haul probably but otherwise its a waste of money

 

No!!! Your cummins is not broke in. The rings need high temps and rpm to seat properely. You are using the best diesel as a commuter vehicle! Need to drive that puppy for 25K hard before switching to syn as a commuter.... Side note, why are you guys driving these trucks????

 

IMO you are incorrect.
I think better fuel mileage, easier winter starts, and a much smoother running engine with extended drain intervals is worth the investment
I will admit that I would have switched at the first oil change but even Cummins said to wait.
Perosonnally I would NOT use MOBIL 1 becasue it is a dino based oil and NOT a true PAO.
Try AMSOIL, Royal Purple or some other brand.

 

Not sure where you got this notion, but I'm afraid you are terribly misinformed. This sounds like some of the hysteria that was going through the rumor mill when synthetics first arrived on the motor vehical scene some 30 years ago. The truth is...Synthetics are FAR superior to organic or mineral oils in several ways (not going to get into that again). The best time to start using them is right after the engine is "broke in" so to speak. 30K sounds like a pretty good mark for these CTDs. Usually it's about 8K for gassers under normal driving conditions.

 

OK...you have my attention. Let's hear more!

 

I'm afraid I do not have the energy to type all that again right now. Please check www.mobileone.com in the FAQs section. Amsoil.com also has a lot of facts comparing the two. You can also do a search on this site, as well as Google Synthetic vs. Organic motor oil.

It's bed time now...

 

Mobile 1 is a true synthetic, mostly PAO (Group IV). RP, Castrol, Valvoline and several others use a Group III basestock. In fact, Mobil sued Castrol over the use of the term synthetic because Mobil contested that Group III oil is not a true synthetic. In Europe, a Group III cannot be labeled synthetic. Mobil lost the case, and in the US Group III oils can be sold as a synthetic.

There are very fewer actual supplies of oil basestocks. Companies like Royal Purple, Castrol and Valvoline simply blend another company’s basestock. I'm nearly 100% confident that Amsoil uses Mobil basestock.

 

Here is my understanding/experiance on the whole deal.

Once you put a synthetic oil in your engine you essentially stop the wear, for the most part, reduce it by 95%, etc. So why is this a bad thing? I have no idea - everyone has their own opinion. I wait until 30k miles to run synthetics because I usually stop seeing any fuel economy improvements around 20-25k miles and my oil change intervals are (Total odo reading) 3k, 8k, 15k, 22.5k, 30k - so 30k is just where the interval lies for me. Every engine is different. Air cooled engines take way less time. The hotter and engine runs the less time it takes. Heat expands metal thus increasing/tightening the tolerances - increasing the pressure between the surfaces (rings to sleeves, etc). Kind of like how hard you push down on sand paper in relation the the quantity of material removed per pass.

To my knowledge synthetics were developed by the Germans from a vegetable oil derivative during the 30's during the war. Their diesel tanks and trucks were locking up after starting in the sub-zero temps because the dino oil wouldn't flow. Well we're a long way from that now.

History repeats itself...

The ZR-1 Corvette came out with the new HO motor and the first 6 spd (I'm not a Chevy guy so I don't know what "L" motor it was) in `92-`93 around there. Kentucky winters are very cold. The factory employees go out to start them up to ship and blow a few motors because the dino oil wouldn't flow. Their cure was synthetic oil factory filled and required from day one. Same with the present Z06.

So does that mean that the engines never break in??? No, they do obviously. Those engines are built to tolerances that our CTDs will probably never see for 50+ years. Why would a vehicle mfg. require synthetic oil from day one if the engine would never break in properly??? They wouldn't.

Sloppy/loose engines have low oil pressure so the "cushion" of oil between the crank/whatever and bearings is less - kind of like running your tires at 15psi and hitting a speed bump at 30mph. You'll most likely dent your rim. But if your tires were at 35psi and you hit the speed bump the same your rim will never contact the bump and the tire will absorb the blow - or your oil in the case of an engine, cushioning the crank from the rod bearings everytime the enine fires (the equivelant of the tire hitting a speed bump). So the tighter the engine is the higher the oil pressure so the better the protection. Why would you let your engine get too loose.

Older engines(`70's) that have ran 100k mi on dino oil then have syn's put in usually begin to smoke because the syn flows much better and get into places the dino oil couldn't - like valve guides, and sneak past the scrubber ring into the combustion chamber. That alone is proof of their superior lubricating ability. Put 20w-50 back in them and they stop smoking. I found this out on my `76 PW100's 318.

You guys figure out what you want to do. It basically comes down to a few questions you must answer:
How long do I want my engine to last?
How long do I want to go between oil changes?
How much do I want to spend on oil?
When do I want to stop my engine from wearing or "breaking in"?
How long am I going to keep the truck?

The benefits and differences of syn vs. dino are really moot. It's just what do you want to do/get out of your engine as answered in the above questions.

Why do I drive a CTD as a commuter, N.Johnson you ask?
21+mpg vs. 14-15 with the Hemi or 4.7L.
400+k mile engine & drivetrain vs. 150k in the gassers.
100k mi warranty vs. 36k mi.
Lower maint costs.
Ability to tow anything I would ever want to buy - I don't know what the future will bring - the CTD can grow/fit any of my possible future needs.
Peace of mind that I will never break a tranny, front diff/axle, t-case, suspension mounts - like I did with 1/2 ton trucks under minimal work usage like towing 3k lbs or less.
Brake pads that last longer than 12k mi like the 4wd 1500's - ties into maint costs.
Resale $10k+ more than gassers for any given age.

All for $4k more than a Hemi. It really makes economic sense.

Just because I don't tow 12k lbs everyday for a living doesn't mean I should have bought a gasser. The CTD gets the same fuel economy as a Crown Vic and has more interior room and a helluva a lot more usefullness. Also navigates snow and ice better than a Crown Vic too. I need a truck and was not looking at cars but this is just some good comparisons/reasons why to buy the diesel.

FYI: V6 Honda Accords, Camerys, etc only get -25mpg.

 

Thanks for all the info! Seems like I have some more miles to put on it before synthetic! I wonder if I should put my BD downloader on extreme for more engine heat - my truck runs at 530 temp cruising at 70mph on the performance mode (CA SO 235 truck).

Another question if I may - its interesting that on this Mobil 1 (truck and suv)bottle it suggests using it on a "GAS" as well as Diesel motors. Is this a better Mobil 1 formula than other Mobil 1 synthetics (for gas engines?)


To N.Johnson:
I do not use my truck as a commute truck. I got a 240sx for that (gets 28-30mpg). Truck is definitely a work truck/family vacation truck (soon, but not soon enough, to tow a boat).

 

What ever oil you use, make sure it meets the minimum requirements as specified in your ower's manual. It must at least meet API CI-4.

Here is some additional Synthetic vs. Organic oil information:

http://www.performanceoiltechnology....dgecummins.htm

Yes...I believe you are correct. The Germans invented the first jet engine, which would and will not operate on organic oil, hence synthetic. Jet engines generate so much heat that organics fry and destroy the engine. The A-1 battle tank is powered by a turbine jet engine, which is why they use Mobile 1 (I don't think goup III base stocks will work - they should be named semi-synthetic anyway).

I like to think of groupIV sythetics like this: they are made up of perfectly round spheres. Organic oil is made up of rods, cones, etc. Try sliding a refrigerator across a garage floor on it's side using marbels (synthetic) between the floor and frig. Now try the same thing but use 3/4" road mix (organics). It's a lot easier using marbles.

 

Go to http://theoildrop.server101.com/cgi/ultimatebb.cgi There is a ton of info there.

 

I will try that tonite at my friends place. Great analogy!

I will tell him its all about science.

 

Great site to know about!!! Thanks for the info!