'02 Chevy Avalanche, standard GM 5.3, 286,500 (mostly highway) miles, whatever conventional oil they use at Plaza Tire.
Made it this far with a diet of that, and no reason to think it won't go quite a bit more.
'04 GMC Sierra 5.3 w/ 110k miles or so on it and currently running RGT 5w30, was using Mobil 1 for awhile when I bought the truck and then PP became the best new thing and was all the rage so I switched to that up until this last change. I purchased it in '06 w/ 42k miles so I've had it 14 yrs and roughly 70k miles.
Honestly when I first switched to the RGT the trucked seemed to run a whole lot better like it had more power but could've just been the fresh oil change but I don't wait too long and run between 5k to 7.5k mile intervals.
Hey...hey...hey now lol Just cause the OP is long gone doesn't mean this thread should get locked or pushed down.
As shown, Many of us here run the 5.3/6.0's and lots has changed in the Engine oil market in last 3 years since OP asked
At moment, I have 3 LSX trucks in my fleet. Oils I currently use are in my sig.
2002 Suburban LM7 with 170K miles running my stash of Chevron Delo 400XLE 10W30 synblend. Its been at my mechanic last 2 weeks getting basic work done then getting shipped up to Oklahoma as a back up vehicle Have only driven it 100 miles or so
2001 suburban with 320K miles. PO was running on 15K of Pennzoil conventional YB ?? 14 month OCI !! Atleast thats what jiffy lube sticker showed ?? It was TEXAS CRUDE black and had to be changed 911 ASAP YESTERDAY !! Used 32oz of GUNK engine flush and poured in some good ole Castrol GTX ultraclean 5W30 flavor as a 2000 mile engine oil break in:! She's running nice and smooth like a "baby LSX" with only 100K on it lol. Mid July next OCI I Might try some M1 5W30 Truck/SUV to see how she reacts lol
On my 01 Silverado HD 6.0 @ 155K miles. I'm Still trying to find the right oil to make my LQ4 run a tad bit quieter and smoother. Just like my crown vic police interceptor she doesn't like the Shell Rotella GAS/TRK SUV in her now
Have a decent supply of Chevron Delo 400XLE 10W30 synblend I got for $5 a gallon @ AZ and maybe 100qts of M1 misc oils Vanilla, EP, EP HM, M1 AP, Super Syn lol
Only ones I'd sell from your group is the Mobil Super Syn and Castrol GTX. My rides didn;t care for those.
All the rest are gravy.... nice stash.
Well, I was using Super Syn 10W30 in my '07 Suburban 5.3 200K miles with the stupid garbage AFM system right before I sold it and she loved it !! OIL PSI was great and no ticking or piston slop. IMO it was good oil
So far the Castrol 5W30 ultraclean has been working pretty good in my '01 Suburban I feel she's a good rig to keep for awhile so gonna switch to a long term oil next OCI. So most likely one of the M1's are going to be used next OCI mid July