10W-40 for Chevy 350

[JBswth]

I've been getting a little bit of blue smoke on startup. I'm thinking of going with a thicker oil. I'm running 10w30 conventional now. What's the minimum temperature I should run a 350 with 10w40? We're talking Texas Winters. Think the coldest it ever got here was 11 degress F.

Your valve stem seals are probably gone. If you aren't using more that a quart every 750 miles, I wouldn't worry about it. In case you are wondering, 10W 30 and 10W 40 are both 10W oil. They have polymers in them so that they will not get thinner as their temperature goes up - 10W 40 has more than 10W 30, so 10W 40 gives better high temp protection than 10W 30. If you ARE using more than a quart every 750 miles, you can try straight SAE 30 and see if that reduces oil consumption a little, as long as it isn't below about 35 degrees outside at night.

 

[JBswth]

The main reason GM and Chevrolet and all the other manufacturers have gone to recommending lighter weight oils, (such as 10W-30) is to reduce their corporate fuel economy MPG ratings. Average to cost millions of vehicles maybe they gain a point here and. I doubt whether an individual would ever see a difference in gas mileage going from 10W-30 to 10W40.
Should not be a problem, as others have said, unless you're operating and very cold temperatures. This is only because it's more difficult to spin a cold engine with thick oil than it is with thin oil.

Now they are telling people to use 5W 30 or even 5W 20. I for one refuse to.

J. B.

 

[SirRobyn0]

Now they are telling people to use 5W 30 or even 5W 20. I for one refuse to.

J. B.

Now wait a second here. There is a huge difference between an 350 and a modern engine. And some modern engines call for 0W20 to.

Setting that aside if you were to pour 10W30 or 10W40 into a modern engine the VVT system won't work and that will set a check engine light. That and those motors are literally built to work with the thinner oils, often synthetic is required. I'm not trying to side track, just trying to give some reasoning to the thinner oils, in modern engines.

I run 15W40 diesel aka heavy duty oil in my square (305), my Jeep (5.2), my Dakota (5.2) my tractor (diesel), all my lawn equipment. My 05' Chrysler T&C gets 5W20 because that's the recommended oil, currently at 230K, other than a set of valve cover gaskets it's never been opened. my new to me 03' MDX gets 5W20 as well 212K.

 

[idahovette]

2015 Tahoe 122000 miles, manufacturer says 0-20. That's what I've run since day one.....May 2015.Still going strong.............that's gonna bite me!!!!!!!

 

[hogdaddy]

In my Gen 1 350 with retrofit roller cam & tie-bar roller lifters, I run full synthetic 10w30.

 

[Camar068]

My 4.3 and LS motors all get 15w-40 diesel oil.

T4, 5 or 6?

 

[Camar068]

Another reminder to me and all. The PETROLEUM QUALITY INSTITUTE OF AMERICA tests a lot of oils and provides that data free. Since I'm on a fresh LS build, I'll be reading up. Previously Amazon oil was above most as almost as good as Amsoil (5w30 full synth)....that what I used in the 100k mile engine and did well with it.

Diesel and Passenger Car links below. Type in the oil you want to see, (right click) open in new browser window. Go back to original screen, select the next to compare....etc. Resize each browser window so you can see them side by side. Make your own decision and learn more on top of that (been a while, need a refresher).

sample comparison, middle one is a sucky result from their website. Be nice if they were all the same format.

HEAVY DUTY DIESEL ENGINE OIL | The Petroleum Quality Institute of America

pqia.org

PASSENGER CAR MOTOR OIL | The Petroleum Quality Institute of America

Passenger car motor oil is the lifeblood of your engine. In addition to lubricating moving parts to help reduce wear and tear and the buildup of heat in your engine, motor oils contain performance additives that help to reduce oxidation, neutralize acids, prevent rust, corrosion, and foam...

pqia.org

 

[Camar068]

BTW....whatever happened to being able to change TEXT color and such? All the tools are greyed out?

 

[Octane]

My 4.3 and LS motors all get 15w-40 diesel oil.

I ran 20/50 for most of 330k miles with no issues in the south here,in my 4.3

 

[Octane]

Your valve stem seals are probably gone. If you aren't using more that a quart every 750 miles, I wouldn't worry about it. In case you are wondering, 10W 30 and 10W 40 are both 10W oil. They have polymers in them so that they will not get thinner as their temperature goes up - 10W 40 has more than 10W 30, so 10W 40 gives better high temp protection than 10W 30. If you ARE using more than a quart every 750 miles, you can try straight SAE 30 and see if that reduces oil consumption a little, as long as it isn't below about 35 degrees outside at night.

My 77 k10 350 smokes a bit after sitting for a day or two.It burns 1/2 to 1 quart of oil every 3000 miles.

 

[Camar068]

double posts clean up.

 

[Drauka99]

T4, 5 or 6?

T5 in all my vehicles, T4 in tractors and lawn equipment.

 

[GTX63]

Today's motor oil is not your papaw's motor oil. Know what is in them and why.

xc_hide_links_from_guests_guests_error_hide_media

 

[Trucksareforwork]

T5 in all my vehicles, T4 in tractors and lawn equipment.

Why is it that I thought you didn’t want to run diesel oil in a car with a cat because zinc or other additives would slowly kill your cat(alytic converter)?

Edit: GTX’s video is great and is similar to what I though.

I run rotella T4 or VR-1 in all my flat tappet engines but just run what the manufacturer recommends in “modern” engines with rollers (1990 and up?).

 

[SquareRoot]

LOL. The new guy stumbles in and mumbles something about oil viscosity and off we go...