Dexos... High Mileage oil

I know everyone has an opinion and I don't want to start a civil war but.... I could not find a thread about this question. Getting ready to change all the fluids in a new to me 2006 Z71 Tahoe 5.3 with 210,000 miles. I have always had good luck with Castrol oils all the way back to high school in the early 70s, but their "Edge High Mileage" now has a new label and does not have the "Dexos" rating on it like it used to. Seems like it is hard to find an oil that has both, What is the latest on the 2 technologies? Are they snake oil to get your money or does one or the other, or both, really do something?
Any opinions or suggestions.

i just run mobile one full synthetic in everything. its cheapest at walmart, at $25 for a 5 qt jug. i end up buying 3 of em a year. my hoe takes 6 qts and my camaro takes 8-9 qt's.

1st, stopped trusting Castrol ever since the 'elves' stopped making green Euro 0W30; I no longer trust any Castrol synthetic, and I only use synthetic.
(1a. I used to be able to comprehend 'bobistheoilguy', but now it just gives me a headache ...)
2nd, since your '06 is no longer under any warranty, nevermind Dexos, another standard that has gotten WORSE at protecting older engines,
which I suspect is Dexos's actual goal.
3rd, high mileage blends are also bullschidt.
I VERY STRONGLY recommend
Pennzoil - any FULL synthetic, Quaker State - any FULL synthetic, Mobil1 - any FULL synthetic, or Valvoline, any FULL synthetic.
IFF your engine has NO leaks and you drive VERY GENTLY, you MIGHT get away with 0W20 or 5W20?
Used to use those til I got the tiniest rear main seal leak that pretty much forces an oil change every 3000 miles,
so now I use 0W30 for the winter, 5W30 otherwise.

I'm presently falling for Valvoline Restore & Protect's ad hype, as Valvoline makes both motor oils AND motor oil additive packages.

Marky Dissod said:

IFF your engine has NO leaks and you drive VERY GENTLY, you MIGHT get away with 0W20 or 5W20?

Click to expand...

What is your reasoning for going with lighter oil?

a) IFF MpGs are a very high priority. I lost 1 or 2 highway MpG switching from 0W20 / 5W20 to 0W30 / 5W30.

b) Regarding 0W vs 5W, stick a bottle of 0W-- and a bottle of 5W-- in your freezer overnight,
then pour them out ASAP. More 0W-- will pour out quicker than 5W--.
In the winter, the first few seconds before the engine idles in Park under 625RpM,
are as important as how you drive during the first 10min.

Pretty amazing how hard it is to figure out the oil maze these days. Seems like you can't get a straight answer from anyone. Used to just use Havoline 10w30 and 10w40, keep it reasonably changed, engines run forever. I'd put 10w30 quality standard oil in that LS motor.

Even some Mobil1 'lovers' forget that Mobil1 makes 7 5W30, 7 0W20, and 5 5W20 motor oils.

I'd use the oil in the weight specified in your owners manual except I use full synthetics now...I like the Dexos label (currently Dexos 1 Gen3) but it isn't required as our vehicles predate Dexos...

...also remember that not having Dexos on the label doesn't mean that oil doesn't meet or exceed just that it doesn't have the license for it...if that's important to you, by all means, use the one that has the license...

most any full synthetic oil in the proper weight will far exceed what came in our vehicles when they were made...I've used Farm and Fleet 5W-30 (supposedly a Citgo oil), Quaker State Full Synthetic and Mobil 1 5W-30 oils without issue...

good luck with your choice...

Bill

Thanks guys. I read and watched YouTube last night until my eyes were blurry. I have about come to the decision that the high mileage is just a gimmick except maybe some seal conditioners and if I don't have any leaks now, why would I want to mess with adding anything. If I get a leak, I'll fix it.
As far as the Dexos label... Thanks SilverSport for making me check, (read the directions dumb a$$). I just assumed since my newer Silverado called it out, all LS's called out Dexos.

Marky Dissod said:

a) IFF MpGs are a very high priority. I lost 1 or 2 highway MpG switching from 0W20 / 5W20 to 0W30 / 5W30.

b) Regarding 0W vs 5W, stick a bottle of 0W-- and a bottle of 5W-- in your freezer overnight,
then pour them out ASAP. More 0W-- will pour out quicker than 5W--.
In the winter, the first few seconds before the engine idles in Park under 625RpM,
are as important as how you drive during the first 10min.

Click to expand...

I agree with everything you said, the MPGs and the cold starts, it's just easier for me to be careful and easy on it when it is cold than when it is warmed up. I may be old, but I still like to kick it every once in a while. The xW20s would make me nervous.