Oil Choice

[Supercharged111]

I'm a wimp: Mobil 1 every 5000 miles. Seems to get guzzled down faster after the halfway mark anyway. I do 0W40 in the trucks and 0W30 in the Envoy and Z06. No need to overthink oil these days. And bear in mind "high mileage" just means it's a spec or more older than what's current. I should probably just do 0W30 in the trucks too.

 

[Supercharged111]

Bought it with 3 years and 35K on it.

I was changing oil when the Oil Life Monitor said I should--about 13K. Sent in oil samples now and then, the only time they ever came back indicating a problem was when the thermostat stuck open. Since I was expecting the oil to be contaminated with moisture, I changed oil (early) when I put the thermostat in, and sent a sample, of course it was contaminated but I'd already changed it.

Anyway, one day I decided that if my oil samples were always reporting "fit for further use", maybe I should just use it some more. That was about a hundred-thousand ago, when I changed the filter at 13K and waited to dump the oil until 26K. It's crossed my mind to add another 13K between changes, but I can't get myself to do it.

How long does it take you to rack up those 26,000 miles? I always thought oil started turning acidic after 6 months? I say this having never had a used oil analysis performed.

 

[thegawd]

man, theres a guy on YouTube who does crazy things with oil and then gets it all analyzed.... friggen crazy. you would be suprised just how well it does perform during his crazy stress tests.... and then he gets the sample anylized.... it's kind of mind blowing. I have no idea what his channels name is..... it's not coming to me.

 

[df2x4]

I always thought oil started turning acidic after 6 months? I say this having never had a used oil analysis performed.

FWIW my trucks use 5W-30 conventional (usually Pennzoil) and I get it changed every 3K miles, which takes me about a year to reach. I've had used oil samples from both of them analyzed by Blackstone Labs and they told me I could go much further on it if I wanted to. I think it takes longer for oil to degrade over time than many people realize.

 

[thegawd]

Absolutely!

 

[HotWheelsBurban]

I've been using Quaker State 10w30 and 10w40 high mileage ( still the same red label but now it's"all mileage"). I was raised to do oil and filter change at 3000 miles, or at least 4000, but the last several have been over that. Hope to get it done this weekend, have to see what the weather does. Supposed to start acting like winter in a few days; 84° today. Sheesh!
Dad always used QS or occasionally Pennzoil in our vehicles, and I have continued that. Also he believed in using the OEM brand filters where possible. So AC on the Burb, PF1218. Haven't had issues with this, I mean at 205,000+ a Chevy 350 is gonna sleep/ use a little bit, but not until after 3K. In other words, when it's " ready " to be changed.
My experience with this regimen on our other 350 Burbs, when I had the pan down, the cylinder bores still had cross hatching visible on them from the original assembly, at 170-200K.
On the other hand, I was never happy with the 2006 truck with the 6.0 LS, telling me the oil should be changed at 7-8K. Not with that teensy filter! I hear LS motors all the time in traffic, at lights, in newer trucks, and every one has valve train noise. And I figure most of them are under my burb's miles too.

 

[Supercharged111]

FWIW my trucks use 5W-30 conventional (usually Pennzoil) and I get it changed every 3K miles, which takes me about a year to reach. I've had used oil samples from both of them analyzed by Blackstone Labs and they told me I could go much further on it if I wanted to. I think it takes longer for oil to degrade over time than many people realize.

My understanding is it's less of a use thing and more of an oxygen exposure thing. How many months are you taking to rack up those miles?

 

[df2x4]

My understanding is it's less of a use thing and more of an oxygen exposure thing. How many months are you taking to rack up those miles?

Like I said, about a year. Sometimes a month or two more, sometimes less.

 

[98chevy2500SS]

man, theres a guy on YouTube who does crazy things with oil and then gets it all analyzed.... friggen crazy. you would be suprised just how well it does perform during his crazy stress tests.... and then he gets the sample anylized.... it's kind of mind blowing. I have no idea what his channels name is..... it's not coming to me.

Would you possibly be talking about Project Farm? His channel is awesome.

 

[Schurkey]

"Acid" in the oil would change the Total Base Number (TBN). Motor oil has additives that make the oil basic (opposite of acidic). As the acid affects the oil, it becomes "less basic". It takes a fair amount of acid to turn the oil "neutral", never mind becoming acidic.

Anyway, that's all a part of the oil analysis; and my oil tests good except when the thermostat fails--as in the Trailblazer, and the '92 Lumina; even at surprisingly high mileage and/or time of use. Some of my vehicles go a year and a half--two years between changes. (Some more than that because I've quit driving them, or they're seasonal vehicles.) I bought my '97 K2500 two (or is it three) years ago this week; and I haven't changed oil on it yet because I doubt I've got more than about 500 miles on it; and it was changed just before I bought the truck.

3000 mile oil changes were maybe a good idea when cars still had carburetors, (rich at idle, rich when cold--fuel contamination in the oil) no overdrive transmissions, (higher RPM vs. speed.) and thick 5/64 rings that didn't seal all that well (extra blow-by.) And, of course, the oil itself has improved.