For those of you who are using synthetic motor oil, how many miles are you going between changes and what kind of driving do you do? I'm debating between continuing with Delo or changing over to Amsoil. I use this truck to commute 20 miles per day total with more driving on the weekend.

 

I currently have 16,000 miles. I'm considering buying the Amsoil and just running it 10,000 miles between changes but want to make sure that I won't be damaging the engine doing so. I guess I could always do the oil analysis a few times to see how things are but I have no idea where I would send it. If I can extend the intervals so that it doesn't cost me more in the long run to use the synthetic, then I'll go ahead with doing that. Right now I can get 6 gallons of the Delo for around $32 at Costco so its pretty cheap.

 

Thanks for the info on the testing company. What do they charge? From my research so far, it sounds like the synthetic is by far the better way to go. I'm just trying to get an idea of how many miles I can go on a change.

 

Ya, I'd be happy with 50k on an oil change. Heck, I'd be happy with 25k. This may be a dumb question, but where do you take the sample from, the oil drain or just out of the filter? How often are you changing your filter(s)?

 

I just changed out the Amsoil 15W-40 HD diesel and marine oil out of my truck this week. It was in for 5 months/8K miles. This was the first fill of synthetic in my CTD that I know of, and winter is the hardest typically on motor oil, so that's why I chose to change it out. No by-pass filtration, just full flow filter. According to Amsoil, the service on this oil is &quot;up to two times the normal change interval or six months, whichever comes first.&quot; According to my owner's manual, that translates to 7,500 - 15,000 miles, or six months. If using an Amsoil SDF full flow filter, that should be changed at 7,500 mile intervals. If using another brand filter, it should be changed according to the manufacturer's recommendations. I actually use the Fleetguard Stratapore filter and changed it once. <br><br>Amzoil offers 4 different diesel oils, a 5W-30, 15W-40, SAE30, and a 15W-40 synthetic blend. Of the 4, the synthetic blend is the only one API certified that I know of. I guess I'm not too concerned about warranty. The 5W=30 is the most expensive of the 4. I'm looking at using Mobil Delvac 1 5W-40 synthetic for next winter. It provides excellant cold weather flow, while still being a 40 weight oil, more readily available, and competitively priced in the &quot;true synthetic&quot; lube oil line. <br><br>I can tell you, you're probably not going to be saving any money going to a synthetic. If you plan on keeping your truck for a very long time, then I'd say it's a benefit. I doubt, though, it's going to make it worth any more if you plan on trading it in soon. I've seen some impressive wear numbers on Chevron Delo 400 using by-pass filtration. <br><br>Just My Opinion! Regards

 

I switched to Amsoil at 50K. I run Amsoil oil filter and have no bypass filter. I am now at 64K and had analysis done at 63K. With 13K on this oil the results state that the Copper and Iron are a little high, 86 and 94. They said they want to watch it and see what it is at the next sampling period. They neglected to suggest a &quot;next sampling period&quot; though, which annoys me because I figured they'd suggest something.<br>Anyway, when the analysis says to change it I will change it. I am suspecting 15K at this point, and I will resample again then to see.<br>As far as where to get the sample from, I got mine from the middle of the oil filter when I changed itout at 13K. When I change the oil again I will be installing a valve (from GenosGarage.com) in place of the oill plug for easy access to the oil in future sampling and of course, easier oil changes.<br><br>Chris

 

Ya know, I'd been running Rotella Synthetic in my '02 during our cold winter, and had just passed the 8000 mile mark when I had an analysis done. It came back fine with advice to change the filter and continue running it. But it dawned on me, what would happen if I needed engine warranty? I'm betting that a good oil analysis wouldn't hold up if I had, say, 20k on the oil and something catastophic happen to the engine. So with that in mind, I dumped the synthetic at the 8500 mile mark, and switched to plain Rotella, and do the standard 7500 mile changes. For me, it just isn't worth gambling with the 100k engine warranty to do extended oil drains. I may be off base, but it gives me peace of mind. And Stamey, the oil valve makes sampling a cinch. You'll love it.

 

105,000 miles on mine with dino oil ( shell rotella )..ill keep using dino.....i personally like the idea of the more frequent services, that way i get to be under the truck and check everything out. used amsoil in my buell 1time still changed it at 3000 mi though..just the idea of the dirty oil in there again its just my opinion.......scott

 

It seems a while back there was a link to a test that was done on the different oils and from my recollection, the synthetics did perform better but the Delo and Rotella also performed very well. I'm thinking at the price I can get the Delo, I'll stick with that and keep the normal change intervals. I also like the idea of the valve that Geno's sells to make it easier to get the oil out.

 

I put the Amsoil 5W-30 HDD in and an Amsoil dual remote by-pass filtration system on the truck with 5050 miles on the odometer. I change the full flow oil filter at 10K intervals and the by-pass filter element at 20K intervals. I also do oil analysis at 10K intervals. Have almost 60K on the truck now and the last analysis with 50K on the oil was still good to go. There was some elevated copper a while back but Oil Analyzers noted it was most likely lechate from the oil cooler based upon past experience with Cummins and Cat diesels. This has dropped off with the last sample. The viscosity and additives remain almost like new oil with the last sample and TBN just began to drop slightly. I'll be sending another sample in about 4K miles. I drive about 25K per year and tow a 34&quot; triple slide 5'er about 6K miles annually. Miles to work are 19 one way.