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What oil do you recommend?

Daniel Cassany

New Member
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Location
North Port FL
A few weeks ago I bought a 1998 GMC K3500 6.5 Turbo Diesel with 205.000 milles in it. What oil do you recommend? how many qt use this engine?
any special recommendation on brand or filter

Thanks?
 
See Above for the oil.
Wix/napa gold for the filters. Most other filters now are junk.

As to the dual primary filter units I don’t like them, but a bypass secondary filter is good.
I think the Frantz is still the best unless you can get full pressure (105-115psi) going through the centrifuge units.

The centrifuge kit Leroy sells is a good option, and easier than what I will do.
I plan to do a 120v pumped centrifuge and just use 2 hoses that cycles the oil pan to pump with self closing quick connects and in an hour the oil can be as clean as new. More work to set up and more expensive at first for sure. But long term (100,000 miles and more) will be worth it and get filtering down to the 1/10th micron.
How small the centrifuge cleans is based on psi input. There is a chart I saw hears ago that shows how clean it will do based on psi of your engine.
 
Are you working this engine hard? If so the oil change interval is 2500 miles.
They take about 8 quarts.
Wix XP oil filters are about the best out there at this time.

I have extended the range on my oil, but, it required gapless rings to do so. IDI diesels are dirty engines and thus hard on oil.
 
The oil w/tungsten is the best bet and BIGGEST BANG FOR THE BUCK.....I recently had a cooling system failure that dumped all the coolant in seconds in an engine treated w/tungsten nano particles and I was in a dead zone for cell service so I drove a distance that would have taken out any engine "seriously" with temp gauge pegged and without any engine damage whatsoever. "No stalling hesitation nothing out of the norm but a pegged temp gauge and hot as hell engine which I slowly cooled down as not too crack block."
 
I recommend Rotella T-6 full synthetic 5-40 weight.
It seems to show slightly lower on the oil pressure gauge in the summer when the engine gets quite a bit some warmer, but, that engine cranks quit a bit faster when the temps gets cold. zeros and below Fahrenheit.
I would like to try the oil that @Twisted Steel Performance sells but just can not afford that for now.
I dont know how good they are or, who makes them, I been using the Mobil one filters too.
 
I sell TriboDyn lubricants, several here use it, test have shown it is the best protection available...

If you want a copy of a independent test performed in Finland it's posted below ...


What do lab reports via sampling say as far as intervals for oil changes, I'm not a proponent of arbitrary oil changes by mileage based on ??? I prefer intervals as indicated on lab results of how I operate the engine, based on my lab tests I change my Amsoil synthetics at 25-30K when additive package starts breaking down or elevated other contaminant indicates need for change, I sample every 5-10K and based on the result I'll consider oil change if warranted. I run a dual filter/bypass filt arrangement on my truck

So I'm curious if there has been any information presented how long one could run between intervals ?

The test result above in PDF file indicates this TribDyn is superlative to oils it was tested against, so I'm leaning that direction, I'm curious however what interval recommendations would be to start with.

Also since we know how difficult to purge all oil from a system what if any are there any intermix concerns before one could begin an accurate oil sampling routing without intermixed oil skewing the result?
 
@Turbine Doc , TriboDyn recommends 20K plus, but advise the same as I do, sample along the way every motor is different. Their are testers that are above 30K miles and the sample says to keep going...

I have been using it for several years, I am on the testing/proving team. My 6.5 shows 1.5 - 2% better fuel mileage, I have their lubricants in the diff, tranny, transfer case, power steering. My motor runs smoother with less noise. The diesel only goes about 5K miles a year, I haven't changed the oil in 3 years, I will be pulling a sample this summer, the motor has 240K miles. I use it in everything on the farm, wife"s toyota, my ranger, 3 tractors, mowers, etc..

I can't give personal sample results at this time, I should be able to later this summer, the toyota has 30K miles on the oil so it's time to sample ..

I have been told their are a few different sampling company's out their, I'm not sure they all know of this oil, I suggested last year a a sample of the same oil be sent to each testing company to compare results, one came back way way off from the others, it seems the most constant company is Blackstone labs, their is one that promotes amsoil and seems to favor that brand on samples, I don't know... Blackstone doesn't recommend any brand that I know of..
 
No matter how long the oil goes, I change filters based on the manufacturer's stated oil change interval. For the motors that support extended drain intervals, the filter changes multiple times over the oil's life. For the motors that trash the oil from fuel dilution (only, and not from particulates) and need changing more frequently than manufacturer's recommendation, I sometimes leave the filter in place and change it on the following oil change.

As to analysis companies, while I get it that some love Blackstone, I find their turn-around times arguably excessive (takes multiple weeks) and inconsistent (sometimes takes over a month). A year or so ago I was talked into going with Blackstone and to compare their results with the company I normally use. Yes, the plan was to send in a sample to two different companies to compare results. Am finding that Blackstone's results are fairly consistent with the other company, but use rather flowery positive language in the narrative versus the other company which provides more technical language and includes watch areas in their narrative. Am not so sure that Blackstone's flowery language is appropriate as those gas motors trash the oil from fuel dilution and I change the oil a *lot* sooner than their manufacturer's recommendation (based on analysis).

After using the last Blackstone sample kit I have in stock, am not going to go with them any more as the competition costs about the same. The big advantage of the competition is that three business days after shipping the sample, I get my results (even during COVID restrictions). And, Yes, the competition company has a baseline of the oil I use in the gas motors as I had to pay for it (for the benefit of everybody whom follows).
 
Ok: Oil Analyzers. Turn times have remained the same over the years. And consisent to the point where I could continue driving on the existing oil while waiting on analysis results to help make a decision on whether to keep the lube for another interval, or buy more and change it.

Point is, Blackstone is Ok for those whom want to wait. If looking to make a decision on whether to change oil in the money maker / daily driver, advantage goes to the competition.
 
I use a local lab: Lab One Inc. The key to good oil samples is to be using the same oil in the engine. Switching brands to what's on sale can mess up your results. Switching to synthetic can flash copper high from the oil cooler on some engines.

Other than finding the limits of the engine oil... Oil filters are really cheap and not all have caught up with the extended drain intervals. Further defective oil filters run for a long time are just that: useless.

Most oil brands are close enough with exceptions like TriboDyn. Synthetic vs. conventional has clear advantages esp. for high heat tolerance. The real consideration for most should be the oil filter.

@MrMarty51 The Mobil1 oil filter is made by The FRAM Group. That company in total has changed hands again recentaly, but, there was a TDR post of a OCOD FRAM that took out a 6.7 Cummins. It was a long Royal Cluster F to get the administrator company to pay for the engine. Most wouldn't use FRAM Toilet Paper, but, may be surprised at who owns and makes what. I was and their "I don't Care Attitude" over a defective filter I wanted to report means you are wasting money on the Mobil1 filter.

I wouldn't use a Wix plastic body fuel filter on a Duramax, but, locally it's the best oil filter available before I go mail order. The XP has wire backed media as new strength. Unlike the E-Core ACDelco cheap cheap cheap design I won't put on my engines anymore.

https://www.thetruckstop.us/forum/threads/mobile-1-oil-filter-failure-or-defect.44531/

Tear-O-Later : Purolator in a Bosch can. They are toast (failed) at 3000 miles.

 
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Good info folks, I've used Oil analyzers mostly, and Blackstone on occasion, I run either Amsoil filters or Baldwin, case priced Baldwin have done very well for me ( I'm almost out of the last case of filters bought 10 years ago). I have one of the earlier Amsoil dual filter remote kits with adapter fitting for the Baldwins I bought from John Kennedy in about 2001.

My rig was parked for a good while as I had a company lease car for 4 years no need to drive the rig, and when fuel prices got so high I was using my 90 C1500 4.3 L gasser as my daily driver.

I've been using my 6.5 truck again as my daily driver since last summer, when the frame on the gasser by steering box was rotted away too much immersion in salt water and it being 1990 vintage.

It looks like I need to maybe migrate to this new to me oil and see how that pans out.

When I was driving the 500 mile commute to work in GA from MS 1500 mile weekly on avg. adding in local driving with the commute I was sampling more frequently , & I kept my "next sample" kit on the shelf to help mitigate wait times I was sampling every 10-15K miles.

This also was when I shifted from the TD07-22A Mitsubishi turbo to the ATT so I had some consistent data points, at same time I dropped the IC as I found I didn't necessarily need it with the ATT & not towing heavy, and probably not needed with the TD07 either but since i had it I ran with it, the IC was needed (mandatory almost IMO) for the original GM-8 turbo once running 10+ psi boost levels and the GM-X turbos being inefficient at high boost levels .
 
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I use a local lab: Lab One Inc. The key to good oil samples is to be using the same oil in the engine. Switching brands to what's on sale can mess up your results. Switching to synthetic can flash copper high from the oil cooler on some engines.

Other than finding the limits of the engine oil... Oil filters are really cheap and not all have caught up with the extended drain intervals. Further defective oil filters run for a long time are just that: useless.

Most oil brands are close enough with exceptions like TriboDyn. Synthetic vs. conventional has clear advantages esp. for high heat tolerance. The real consideration for most should be the oil filter.

@MrMarty51 The Mobil1 oil filter is made by The FRAM Group. That company in total has changed hands again recentaly, but, there was a TDR post of a OCOD FRAM that took out a 6.7 Cummins. It was a long Royal Cluster F to get the administrator company to pay for the engine. Most wouldn't use FRAM Toilet Paper, but, may be surprised at who owns and makes what. I was and their "I don't Care Attitude" over a defective filter I wanted to report means you are wasting money on the Mobil1 filter.

I wouldn't use a Wix plastic body fuel filter on a Duramax, but, locally it's the best oil filter available before I go mail order. The XP has wire backed media as new strength. Unlike the E-Core ACDelco cheap cheap cheap design I won't put on my engines anymore.

https://www.thetruckstop.us/forum/threads/mobile-1-oil-filter-failure-or-defect.44531/

Tear-O-Later : Purolator in a Bosch can. They are toast (failed) at 3000 miles.

Thank You very much War Wagon for the information on the fram mobile 1 filters. I have a brand new one in the back seat of the truck, it will now go directly to the trashing can. I aint a taking any chances of having a filter crap out and destroy this engine. It has to last Me for a very long while.
 
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