I just ordered a 2005 gmc sierra 2500hd with the duramax/allisson combo. it is expected to arrive at the end of this month. i was curious as to when i should switch it to synthetic oil. i live in northern MN and it has already been below freezing several mournings. could you please give me some advice. this is my first diesel

i know theres a lot of opinions out there on this one but i for one say
stick with regular oil in the engine and change more often - this is
just MHO from research conducted on the subject. If youre talking
about tranny and diff, then go to the synthetic - both can be changed
out anytime but i think most people opt for the tranny change at
various times, i was going to after 3000 miles but did a SC 3 in and it
was done at that time, the diff i did after 3000 miles, and first oil
change was after 3000 miles, however, i did put synthetic in that time
as the first oil change and have since started changing every 3k with
regular oil. everyone will have a diff opinion on this and i know
someone posted a rec list on the lly forum of items to change and when
you might want to reference as well

I'll be doing mine on my 3rd oil change. 10,000km's or about 6000 miles. Perhaps a bit early but it will be getting really cold here by then and I am now a believer in synthetic oil.

There's been considerable debate on engine oils and filters, not just on the DP. Before I forget, stay away from Fram filters. For every point someone makes on oils someone will come along with a counterpoint. We tend to be a bit opinionated on the ole DP! http://www.dieselplace.com/forum/smileys/hihi.gif Trust me, my post will be no exception.


During break-in I changed my engine oil at 500, 1200 and 2500 miles based upon input from several of the guys on the site that appear to know their stuff. I could tell a significant difference after the first oil change, the truck didn't lunge while idling through parking lots. Each subsequent change had similar results with better performance. At 4400 miles I switched to Mobil Delvac 1300 and plan to go synthetic at 10k miles.


While there is much discussion about the quality of dino oils and their ability to maintain their lubricating properties at very high temps as well as residues they may leave behind, the synthetics don't appear to have the same chemical properties and appear to run longer and cleaner. DISCLAIMER: I ain't no oil expert, just basing this upon what I have read on this and other sites.


I have towed heavy for years and always ran synthetics in my gassers. Noticeable difference when letting off the accelerator, far less restriction on the motors. Is JJ crazy, maybe? http://www.dieselplace.com/forum/smileys/smiley5.gif


Check out posts by LanduytG(?), he is a lubrciation specialist and knows his stuff. My personal idle I might add! http://www.dieselplace.com/forum/smileys/Rock On.gif He is an Amsoil distributor, but is very good at remaining objective and not boxed into just his products. JJ http://www.dieselplace.com/forum/smileys/smiley4.gif

i agree with you max power. i also am a firm believer in synthetic. what brand of oil do you recomend though?

what do you guys feel is the "believer" point to which makes it better ? please dont take this wrong, im just trying to gather information on this subject, thanks again

i agree with you max power. i also am a firm believer in synthetic. what brand of oil do you recommend though?


I run Mobil Delvac 1 5w40. I run it because i know it is one of the best and it is easy for me to get here. The price is a bit higher then other synthetics.

what do you guys feel is the "believer" point to which makes it better ? please dont take this wrong, im just trying to gather information on this subject, thanks again





-37 degrees, breaker blew and it still started. http://www.dieselplace.com/forum/smileys/smiley9.gif


In extremely cold temperatures it cranks over a lot easier and you have instant oil pressure. I see a lot colder climates then most so I feel my truck deserves every break it can get.

ahhh, very good point max - and im with you on that one !! im sure it definitely help you out in that weather up there - do you change more frequently ??

I believe due to heat capability. Insurance so to speak. Had a gasser get so hot it seized due to a stuck thermostat. Cooked the gaskets, etc. but the oil stayed together. After it cooled down (over 45 minutes before it stopped flash boiling and shooting back at me) I removed the theromstat and drove it home. I changed the oil imeadiately and fully believe that engine would have been a goner had I not been running a synthetic oil. Still runs and doesn't burn any oil. I can pay for the extra cost of synthetic for a looong time before it costs as much as an engine, especially a Dmax.http://www.dieselplace.com/forum/smileys/smiley4.gif So my thought is if something goes wrong, whether it is the engine, tranny, differential or transfer case, I have a better chance of limiting the damage or getting home with synthetics. I still change the oil on the dino frequency using the wonder system or 7500 miles, whichever comes first.http://www.dieselplace.com/forum/smileys/hihi.gif

ahhh, very good point max - and im with you on that one !! im sure it definitely help you out in that weather up there - do you change more frequently ??





On synthetic I change it at 10,000km (6200 miles) intervals.

I think the question was "when" to change from dino to syn, not "if". I
have the same question. So far only one answer: 10Kmi. Any others?



I had first change at 1,800mi (and changed rear diff fluid). I am
planning next one at 5K, which will also be the time for tire rotation
and change of Allison spin-on. After that, I was wondering if to wait
until 10K or 8K before changing over to Syn.

Cool handle "whitesnake01", If you read the posts on oil change intervals you'll see guys changing to syns at various intervals. I'm from the old school that you run dino until valve seats and pistons have seated properly before running synthetics. 10k miles has always been the mark. No scientific data to back that up!


Dangit, your post reminded me I need to get my tires balanced and rotated. JJ http://www.dieselplace.com/forum/smileys/smiley4.gif

We Installed my Nicktane pre-filter and performed my first service today - at 1,357 miles.



Amsoil SDF52 filter and ten quarts of Amsoil 15W40 full synthetic. I'm
currently thinking about changing the filter every 5K miles and the oil
and filter every 10K. Looks like every 10K will satisfy the DIC oil
life indicator.

Switched mine at 500 to Delvac 1. Changed out original fill at 250 with dino. Some manufacturers factory fill with synthetic. In my work trucks, I change every 2500 with dino. Why synthetic in the Dmax? I have no idea. Just seemed like the right thing to do. I change the synthetic out every 5k.


Some have told me I'm crazy, that I can go WAY longer on oil changes. In the long run, oil is cheap, and I can say that I have never wasted a motor by changing the oil too frequently.


Ty

Just curious. Any warrantee issues to be concerned about? Does GM recommend a particular syn?

I'm in South Texas, any recommendations on which weight to go with when
I go synthetic? I should be hitting 10k miles sometime around Mid
November / December timeframe.



Also, where should I get the Amsoil from? Any San Antonio Distributors?

I would change oil at 3K, 6K and 10K go to synthetic.


Should be no warranty issues as long as it is API certified.


Corona, Running up here in Dallas with the 5-40, my pressure was below 30, but above 25. That is a little lower than I would like, but still "acceptable" according to everything I have read. Down in your area, I would probably stay with a 15-40, but wouldn't rule out the 5-40 is the Delvac is what you have in mind.


I think there are quite a few new cars rolling off with synthetic in them. I think it would slow down break in, but definitely not eliminate it. I wouldn't do it quickly because I think you should run dino and change very frequently to get the casting sludge out at the beginning of the engine's life. That is more of the reason as oposed to breakin.

Hey JJ,


You said at 4400 miles you switched to Mobil 1300. What did you use before then?


I personally drained the factory fill at 600 miles and replaced with the Mobil Super 1300 15-40 along with a new OEM black filter. Then I dumped that oil just last weekend at about 1600 miles and again replaced with more Mobil 1300 and another OEM black filter. I think I might have to push the synthetic a little sooner than the 10,000 mile mark because the weather is going to be getting COLD here soon, but from all the gurus I've talked to, they really don't think that this should be a problem at all.


If you'd like more oil advice, I'd suggest visiting www.bobistheoilguy.com (http://www.bobistheoilguy.com) for more info. They're very helpful over on that board I've found. Hope this helps.

Change my oil 3 times in the first 2100 miles. At 2100 I switched her over to synthetic. now have 12K miles on her and I will be do my second oil analysis. At 5K miles all was well.





Greg

I had the oil changed at Jiffy Lube with their Pennzoil brand for diesels. It's actually not too bad of an oil. I figured I was only going to run it about 800-1000 miles max and ran me about $40 per change.


I think bobstheoilguy's website is where I found most of my intel before joining TDP. Wouldn't you know LanduytG would post he changed to syn at 2100 miles. Broke my heart! http://www.dieselplace.com/forum/smileys/hihi.gif If he changed that early I wouldn't be afraid to, like I said the guy knows his stuff when it comes to lubricants (that sounded kinda kinky!). http://www.dieselplace.com/forum/smileys/smiley36.gif


Like I said I haven't seen any hard data that waiting til 10k is better, just have always heard that and done that! JJ http://www.dieselplace.com/forum/smileys/smiley4.gif

Duraden. There are no issues with syn and warranties.

As long as the oil meets GM's requirements there should be no problem with warranty..

API Certified (with API logo) 5W40 or 15W40 (Dino or Synthetic) Diesel Oil with CH-4/CI-4 rating.
http://www.dieselplace.com/forum/smileys/smiley23.gif