Oil Recommendations

[oldelpasso]

Hey Guys,

My 1997 Silverado (V8, 5.7L Vortec, RWD, 173,000 on the OD) is new to me, with no prior history on maintenance. I've only had it a couple of weeks, so I don't know what oil is in it, whether it's synthetic or conventional, or whether or not it burns any oil. I'm proactively changing all fluids due to the lack of maintenance records.

I'm planning to run 5W30 per the manual, and likely will run High Mileage. Your recommendations on Synthetic vs. Conventional will be appreciated.

-OldElPasso

 

[HotWheelsBurban]

My 99 Burb 5.7 has 206K on it, we got it with 136K. Every oil change has been with 10w30 or 10w40 (depending on if summer or not and which one I can get) Quaker State red label. They used to call this High Mileage and now it says All Mileage. Mine sees Houston, Texas area traffic every day and I have good oil pressure ( for an old Vortec anyway) and no clattering. 5weight might be good for a new engine or an LS but my opinion is a 350 needs what I use. This is our 8th Burb, almost all with 350s, and that's the oil I have used in all of them. Some of those 350s went way past 300K on that regimen....

 

[oldelpasso]

Do you run Synthetic or Conventional?

 

[Lou Merrell]

I run Oriellys full synthetic store brand.
It's actually made by Mobil. My truck has 180k

 

[Schurkey]

I put "synthetic" in everything including my riding lawnmower. When I run out of my current supply of "synthetic" oil, I'm considering spending extra to buy real synthetic oil.

REAL synthetic oil (Group IV) is expensive; but here in America we can buy "synthetic" (Group III) oil made from...oil...at reasonable prices.

Our "synthetic" Group III oil (made from oil) can't be sold as "synthetic" in Europe--but America's politicians are the best that Corporations can buy. (And some of our courts are run by the stupidest judges.)

Group III base oils are considered mineral oils by many technical people because they are derived directly from the refining of crude oil. However, they are considered synthetic base oils by other people for marketing purposes

www.machinerylubrication.com/Read/29113/base-oil-groups

Base Oil Groups Explained

Almost every lubricant used in plants today started off as just a base oil. The base oil category defines what the oil is made of, how it is manufactured, and how the lubricant handles certain environments such as extreme heat.The American Petroleum Institute (API) has categorized base oils into...

www.machinerylubrication.com

 

[HotWheelsBurban]

Do you run Synthetic or Conventional?

I think the QS is a syn-blend, but I'm not looking at a bottle right now.

 

[GoToGuy]

Mobil 1, in everything, according to vehicle specs. All vehicles I've owned since 1980.

 

[oldelpasso]

Thanks guys for all the advice! I went with Mobil 1 10W30 High Mileage. I'll keep an eye out for leaks, and noises, but don't expect any issues.

 

[eran tomer]

don't you pay attention to API classification?

 

[tsr2185]

Thanks guys for all the advice! I went with Mobil 1 10W30 High Mileage. I'll keep an eye out for leaks, and noises, but don't expect any issues.

any updates after this swap?

I plan to run 10w-30 syn blend on my 91 w/ 280k miles, ~120k on a gm crate engine. I ran Castrol GTX conventional 10w-30 first few oil changes. When cold, oil guage is pegged out around 60psi, hot around 15psi (no plans to put mechanical guage on it).

I was looking at gtx high mileage syth blend, but I hear a lot more people using mobil synthetic blend. Probably gonna use Mobil 10w-30 syth blend next change. Oil is still very clean after 2k miles.