To Synthetic or not to Synthetic

[Smokin Joes 2500]

Ive got 19,000 miles on truck and do to change oil in about 150 miles. Im thinking of taking the plunge into 5w40 diesel synthetic. Is my truck "broke in" enough to start the synthetic. Also if I do switch over how much more can I safely extend my change intervals.



P. S. will be ordering Amsoil BMK11 next month.

 

[Bodie]

I started mine at 15k. No leaks or problems.

 

[SDunkle600]

I am in the same position as you SmokinJoes and was wondering the same thing. I will stay tuned and see what the responses look like.

 

[AMassaro]

I've been using sythetic since 10,000 miles. I started with Mobil1 my first cold winter for the better cold flow capabilities. I went back to dino oil that summer, then back to synthetic, ValvPremBluExtreme 5w40. When changing out my bypass filters, I added dino oil to the synthetic for makeup oil. I've had three excellent oil analysis done so far and soon will be doing my forth.

 

[DieselFiend]

I'm using AMSOIL 15-40 and right now I'm changing the oil every 9K. I'm getting ready to send in another sample and if it's good I'll extend it out to 10 or 11K. If I were you and getting ready to switch I'd start out with your first oil change at 6K and take a sample and send it in. When you get the results, decide how much longer you want to extend your oil change intervals. Blackstone will give you an oil change interval recommendation if you send it to them.

 

[1965LONEWOLF]

I Agree With Dieselfiend , I Aslo Started At 10,000 Miles , But I Would Like To Know Where I Can Send My Oil In To Get Checked Out ? If Anyone Can Let Me Know , Please Do.

Right Now I Change The Oil Every 10,000 Miles.

 

[RRees]

I switched at about 3000 miles. No problems.



I'm running Shell Rotella T 5w-40. It's hard to find other synthetics in the Des Moines area. I'll probably switch to non-synthetic in the summer.

 

[kbond]

I think the main concern is trucks with low miles aren't fully broke in yet and would switching to synthetic pro-long the break-in? Ultimately it's a fuel mileage concern.

 

[PTomlinson]

I switched mine at about 6000 miles, not for economy, but because the manual told me that's what I needed for cold weather. However, it hasn't seemed to hurt the break in process as I got 23mpg (US, it was 27mpg imperial) hand calculated last summer on one road trip.



Paul

 

[DPKetchum]

Started at 15k. Cuimmins site recomends between 15 and 20k.

 

[AMassaro]

I Agree With Dieselfiend , I Aslo Started At 10,000 Miles , But I Would Like To Know Where I Can Send My Oil In To Get Checked Out ? If Anyone Can Let Me Know , Please Do.

Right Now I Change The Oil Every 10,000 Miles.

Blackstone labs

 

[J.BURCHFIELD]

100% synthetic is best. It does not break down like dino oil. Changing oil is expensive so I installed a by-pass filter (2 micron) so that extended changes would be OK. Changing filters and not the oil is a good plan. Just be sure to fill the canisters with oil when you change filters so as not to starve the turbo on initial start up. How often you change filters/oil is up to you. All the big trucking companies are saving money on oil by using a by-pass system. Sending an oil sample to an independent Lab is a common practice and would guide you to a decision as to how often to change oil if at all. They also analyze transmission and rear end samples too, if you want to carry it that far.

 

[JSlingerland]

I switched to Castrol Hypuron 15w40 synthetic blend at the first oil change. Zero consumption between changes by the service book. My '05 now has 27000 on it. Its the same oil I use in my Macks and it dropped the oil temp 30 degrees on long pulls. No abnormal wear in the samples either.

 

[amsoilman]

I swithced to the Amsoil 15W-40 Heavy Duty Diesel & Marine (full synthetic) in April of 2003 with 8,500 miles on the ticker. I know have 65,000 on the truck, and over 56,000 on the oil. I do oil analysis every 10K, and the oil is still in great condition.

Last report at 54,800 on oil the Visc. was 14. 7cSt@100*C Soot/Solids were 0. 78 & TBN was 7. 12. I plan on keeping this oil untill it no longer is "Suitable for continued use". This is my 3rd Cummins doing it this way, so I am not worried in the least!







Wayne

 

[DeezelDood]

I was 100% sold on the switch to synthetic in my CTD (have used Mobil1for 30 years in my gassers), then I read the article about lubes/additives in latest TDR quarterly. Recommended reading. I'm still leaning there, but I'm in no rush.

 

[MSanford]

I changed to Amsoil synthetic at 3000 miles on my 06 (which was totaled at 12000) and I believe that I did not allow enough time for "break in". My fuel mileage, tested at the pump, went down about 2 mpg! Might not have been related to the oil change, but my 07 replacement I have not changed yet at 5000 miles and every 1000 miles mileage has increased. Now up to 21. 5 mpg at the pump and I am not going to switch to synthetic untill 15000 at least.

 

[J.BURCHFIELD]

I changed to Amsoil synthetic at 3000 miles on my 06 (which was totaled at 12000) and I believe that I did not allow enough time for "break in". My fuel mileage, tested at the pump, went down about 2 mpg! Might not have been related to the oil change, but my 07 replacement I have not changed yet at 5000 miles and every 1000 miles mileage has increased. Now up to 21. 5 mpg at the pump and I am not going to switch to synthetic untill 15000 at least.

Maybe 25k would be better, give the rings more chance to bed in. My experience was I put in the Amsoil at the first oil change and it took forever to seat in the rings. It was 75k or so before I did not have to add a quart of oil every 1,000 miles or so. That proved to me how good synthetic is. While Amsoil may be the best I believe the others are running a close second. Mobile 1 came out with 5w40 for Diesel use a year or so ago and due to it being hard to get Amsoil where I live I switched. I bet my 98 12v won't know the difference. Wally World handles the Mobile 1.

 

[BillGotthelf]

I have waited till I had 15,000 miles on all my Cummins from my 86 to my 05. Also from oil analysis we are using 15,000 miles as the change interval (using Amsoil series 3000) in the 05 but my 04. 5 has a bypass and I know have 62,000 on the oil and it is fine.

 

[Buffalo]

In my opinion, Synthetics, certainly, have their place in the motor oil world. Cold weather starting & operation & extended oil drain intervals, along with the use of bypass filtration, & the 'feel-good feeling' of using a super high quality oil, come to mind.



It seems to me that those of us that don't drive, that many miles & don't live in extremely cold climates may not really need the costly synthetics. The new conventional oils seem to be of a very high quality. Especially, the Chevron Delo-400, 15X40.



The Delo has a mix of Moly & Boron in the additive package. Makes it quite a robust oil. Some have said that it is approaching the quality of synthetics, now. And for much less cost.



I have been extending my oil drain intervals, using used oil sample testing, & the oil seems to hold up much better than I had originally thought. I used to change at 5000 mile intervals but, read of others having success with much greater intervals. So I went up to 6000 miles, 8000 miles & the last interval was 9626 miles. All samples were tested & found to be, still, in good, useable condition.



I believe that DC requires an oil change, at least once a year, to maintain the engine warranty ( if that's important to you). My oil change with 9626 miles on it was just under one year.



My thinking is that if you don't drive many miles and still have to change every year, to maintain warranty, maybe just using a quality conventional oil may be the best bang for your buck. These oils certainly seem to be strong enough. There are a number of trucks with over a million miles, on them, that have used only conventional oils. If those oils were of poor quality, those engines would not have lasted that long. How many of us will, REALLY, keep our trucks for a million+ miles? This is where the use of synthetics for that 'feel-good feeling' comes into play.



Granted, those that drive an enormous number of miles, using their trucks commercially (as in towing trailers, for a living, etc. ) will benefit from the use of a combination of synthetics & bypass filtration. Many of those people would have to change oil on a monthly basis with conventional oil use. The convenience of synthetic/bypass filtration use, seem obvious.



Joe F. (Buffalo)

 

[MRann]

I run Mobil 1 full synthetic, average about 16 mpg in town and 20+ on the highway. 06 3500 daulie, also pull 11k 5er with no oil loss. I change about 5k, switched to Mobil 1 at 5k, friend in the trucking business swears by it.