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Thread: What motor oil do you use and why?

  1. #1
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    Arrow What motor oil do you use and why?

    What motor oil do you use and why?

    I use Shell synthetic in my Duramax because of the 7500-mile drain interval and how clean the oil remains over the time it's there. And, it's available at WalMart. I might use Mobil Delvac 1 synthetic, but it's much harder to find.

    For a 6.5, I tend to use Chevron Delo because of the 3K drain intervals and the soot load.

    Jim

  2. #2
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    I use the Rotella full synthetic. It has quieted the rattle some. I got another 1+ MPG. It's cheap at the Wallies. And I read a report by a independant oil analyzing firm that said that is the best full synthetic on the market for the light duty diesel engine. That it beats the requirements by a long shot. I'd post the report but I have changed computers twice now since I saved it.
    95 GMC K2500 SLE 6.5L TD, Relocated PMD to bumper #9 res., Custom Lowes special induction tube, Triple guages on the pillar EGT,Trans,Boost, High Idle Mod, TCC-Lock up Mod, Custom Back up camera, DIY Manual Wastegate Controler, 4" from down tube to 5" stacks, Vac Pump Removed,2007 wheels, WMI by CoolingMist 8gph @3psi 11gph on demand

  3. #3
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    Default Shell Rotella Line used here

    The 95 GMC gets Rotella T6 5W-40 synthetic, also running an Amsoil bypass filter. I run 10-12K oil change intervals, but change the PF1218 spin on every 2500 miles and add a quart.


    Have been running RotellaT 15W-40 in the 2005 Dmax and 7500 mile change intervals. EGR disabled since new, oil stays clean, starting to discolor when changed at 7500 miles. Also run with the turbo vanes open during light cruise which also reduces soot in the oil.
    2016 GMC SLT 2500 CC 4x4 Duramax All Terrain 46K
    1995 GMC 2500 EC 4x4 6.5TD,233K,Custom Tuning,HX40W-II turbo,Amsoil Bypass Filter,KD Exhaust,FSD Cooler,KD Headlight booster,Hi-cap Cooling
    TDP member #14

  4. #4

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    Mobil Delvac black jug - 10K intervals
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  5. #5
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    Rotella T 15W40 mineral, 4-5K mile drain interval (8T motorhome loads the engine a lot more than a pickup or Suburban). I was a field engineer with Shell many years ago. I may consider switching to synthetic due to ULSD, but haven't seen a convincing study about the effect of ULSD.
    '94 Barth 28' Breakaway M/H ("StaRV II") diesel pusher: Spartan chassis, aluminum birdcage construction. Peninsular/AMG 6.5L TD (230HP), 18:1, Phazer, non-wastgated turbo, hi-pop injectors, 4L80E (Sun Coast TC & rebuild, M-H Pan), Dana 80 (M-H Cover), Fluidampr, EGT, trans temp, boost gage. Honda EV-4010 gaso genset, furnace, roof air, stove, microwave/convection, 2-dr. 3-way reefer. KVH R5SL Satellite. Cruises 2, sleeps 4, carries 6, and parties 8 (parties 12 - tested).

    Stand-ins are an '02 Cadillac Escalade AWD 6.0L and an '06 Toyota Sienna Limited.

  6. #6
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    Apr 2010
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    Rotella T6 synthetic.

    5W40.

    Yup, I drank the cool aid:

    http://www-static.shell.com/static/c...rotella_t6.pdf

  7. #7
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    Delvac 1 5w40. My 2005 just sold. It had 8,000 miles on the oil (with bypass filtration) and the oil looked like new on the stick just a bit of darkening. Golden look on the stick. Partly oil, partly filtration and even moreso mild yet strong tuning...

    I've gone 12k on my 2007 with no bypass filtration.

    My 2012 got Delvac 1 at 300 miles before our trip to CO

    All trucks still use the factory breather/PCV system. The 2005 and 2007 will consume about a quart in 5-7k.


    My 2002 uses Cenpeco Racing 20w50 (petroleum) due to the extreme naure of operation of this engine.
    Kennedy Diesel-owner
    More than just a salesman-I use and test the products that I sell on a daily basis!
    Superflow Lie Detector in house
    2002 Chev K2500HD D/A CC Long LT 11.77@ 124mph at 7700# fuel only-e.t. needs help
    2005 Chev K3500SRW D/A CC Long LT(SOLD)
    2007 Chev K2500 Classic EC Short LT (Sold)
    2012 GMC K3500SRW D/A CC Long LTZ Happy Birthday to me! Built 1 working day after my birthday and delivered 7 days later.
    2016 GMC K3500SRW D/A CC short LTZ

    Custom tuning in house using EFI Live tuning software!

  8. #8
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    Rotella 5W-40 synthetic, because I can use it in everything I own except the 2 cycles. My oil change intervals are about what they were when I used non-synthetic, but I don't worry if I go a bit over.

    The 6.5s use exactly the same amount of oil as when I ran non-synthetic Rotella, but the oil doesn't get as dark, as quick. Hmmm...

    As my gas cars approach 150K to 250K miles, I get real lax about change intervals. Towards the end, our 02 Century was getting changed twice a year. (My son overheated it at ~ 250K. Neither he nor I realized the gauge never makes it to the red, no matter how hot it gets. So, it wasn't in the red, & he nursed it a mile to work. Head gasket, cracked head - pretty normal for a 3.1. I don't figure the car owes me anything. Was shopping for another Century when a Saturn caught my eye.)
    82 6.2NA K15 4X4 pickup, 4spd man w/ OD, 335K+ "In Rust We Trust" (parked)
    95 6.5TD 2500 4X4 pickup, Gear Vendors Aux. OD, > ¼ million miles - gone
    95 6.5TD 1500 4X4 3/4T Suburban, Kennedy exhaust, > ¼ million miles
    93 6.5TD 3500 4X4 1T crew cab LB pickup, 230k miles

  9. #9
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    Rotella 15w-40 at 5k intervals. I use it because its got a good rep, it's available everywhere, the price is reasonable, and it comes in a 2.5 gallon jug!

    Disclaimer: Rotella's price is starting to get up there a bit, I may try Travellers (TSC) 15w-40 or maybe Wal-Marts brand ummm can't think of the name. They are both almost $5 cheaper per 2.5 gallon jug.

    Of course with oil changes only two or three times a year the extra 5 bucks ain't much of a savings.
    Jeff

    "But officer, I ain't Speedin', I'm just flyin' low"

    2001 Silverado 3500 Dually LS Ext Cab, 6.6L Diesel, Banks Stinger Kit, 4" Exhaust, VR Straps, Bilstein shocks, 255/85/16 BFG KM2s
    2004 Suburban 2500 LT 6.0L 4x4, Bilstein Shocks, Federico front/rear sway bars
    1996 Caprice 5.7L LT1, B4U Suspension, KYB shocks & Hotchkis sway bars, BMR RCA

  10. #10
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    Good Day!

    Wow - I was just in Wally's, & was unaware of how much conventional oil has gone up. Most of the name brands were ~ $3.70 a quart. Rotella 5W-40 synthetic, which I use, works out to ~ $5.38 a quart. I'm glad I read this topic; feeling better about my choice.
    82 6.2NA K15 4X4 pickup, 4spd man w/ OD, 335K+ "In Rust We Trust" (parked)
    95 6.5TD 2500 4X4 pickup, Gear Vendors Aux. OD, > ¼ million miles - gone
    95 6.5TD 1500 4X4 3/4T Suburban, Kennedy exhaust, > ¼ million miles
    93 6.5TD 3500 4X4 1T crew cab LB pickup, 230k miles

  11. #11
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    I ran rotella synthetic for the first 40K miles on the engine. I switched to Mobile 1 synthetic 5/40 because the store was out of Rotella once and I don't think I'll go back to Rotella. Engine was quieter and it burned less than half of what it normally did between changes. After it gets running again I will stay with the M1 for a while. I do plan to add a bypass filter system to it, as well as add some additional oil cooling.
    1987 Jeep Grand Wagoneer...new 6.5 in process...diamond block, 18:1's, other goodies...


  12. #12

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    Agreed. I could never keep Rotella in my engines, was always adding oil as it vaporized off.

    I use Mobil Delvac black jug conventional and do 10K oil changes, which is about every month during the season. I have about 800K happy miles on seven Duramax trucks using this method and brand. I carry no oil on the trucks, never add between oil changes anymore.

    Interestingly, CAT has stepped away from use of multi-viscosity oils (Rotella 15/40 is just as commonly used in the marine industry) in their turbocharged and aftercooled marine engines for the same reason - breakdown.

    As the oil breaks down, it plugs the aftercoolers with sticky black goo that is residual from the additive package that gives the oil its multi-viscosity properties. CAT now requires a straight weight DELO 30W for my boats twin CATs.

    I had maintenance records from the previous owner that indicated Rotella had been used about half the seasons since 2000, so I had the aftercoolers pulled and steam cleaned, engine oil changed to DELO 30W.
    Last edited by Mark Rinker; 10-29-2012 at 05:39.
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  13. #13
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    I also use Delo 30W from Napa.

    Many years ago I talked with an engine builder and his story was that in the multiweights the chemical structure is " played with " and the oil is almost a polymer . He claimed that nothing would " touch " the carbon that was the result of using the Multigrades. He recommended the straight weights.

    I think the multigrades came into use in an attempt to increase fuel mileage when we had one of our gasoline " crunches". Kinda like puting automatic transmission fluid in manual transmissions to reduce the drag of churning up the heavier lubes.

    Just some of my thoughts and observations.

    I prefer Engine mileage to fuel mileage :>)

    Jerry
    1996 Silverado 2500 TD , stock except for a remote mounted PMD.

    I purchased this Truck 7 years ago from the original owner, had 80,000 miles on it. I Had the engine remanufactured at 100,000 by a local remanufacturer that does 6.5 Engines for the Military. Now has 105,00 miles on it.

  14. #14
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    Are there any straight weight synthetics? The previous owner was using a Shell Rotella T5 synthetic blend. I've got about 300+ miles on the truck since I bought it & she does no seem to have much if any blow by. Unknown actual engine mileage. Have I gotten the impression that switching between full synthetic & conventional is a non issue? I have always run Rotella T1 in both my gas & diesels but being out of the loop thought I'd get some more input ~

    Thanks!
    96 1500 6.5 Silverado

    81 Malibu ~ 75 Vega Wagon

    Lecanto, Florida

  15. #15
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    Amsoil, I have 408,000 miles on the cock.
    06 1ton 4X4 duramax/6speed ext.cab WT
    Hummer wheels :^)
    Kennedy dual lift pump
    Banks air intake

  16. #16
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    Quote Originally Posted by spongebob View Post
    Amsoil, I have 408,000 miles on the cock.
    My chickens NEVER went that far. Impressive.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  17. #17
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    I feel like a beginner with only 217,000 on my '06 LBZ.
    Ed
    KM4STL

    '06 Sierra LBZ 4x4 Crew SB, Titan 52 gallon fuel tank, TTT/Schefenacker Mirrors
    '98 Suburban, 245,000 - sold 7-4-06

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