Which Oil Viscosity to use?

[Str8blazin]

A friend brought it to my attention that his brand new car calls for 5w-30. I live in south carolina and it's pretty hot done here. Hi's are in the 90's. I told him that he should run a thicker oil in the summer to make up for the temperature change. He then tells me "well, it's clearly printed on the oil cap." When I looked at mine, I noticed mine said the same. In the Haynes Manual, they have 5w-30 "Preferred", but still lists other viscositys. How can they say "preferred" when they don't know what the temperature is like where the car is? Do ya'll think I should run 5w-30 since it is printed on the cap? Right now I have 20w-50 in it. Also Keep in mind, the Camshaft Posistion Actuator Solenoid, which controls the variable exhaust timing by the amount of oil that flows through it. Would the 5w-30 give it more power since it's thinner? With that said, I believe that it may be almost necessary, to run the 5w-30. I am obviously not shore which to use, and would love to know. Thanks for any help.:confused: :crazy: :undecided

[Dave]

Dump the 20W50 and go back to 5W30. The lower weight is also for cooling and easier cold starts. You might notice a little more power and better MPG. Too thick oil may cause oil starvation.

20W50 oil is usually used in high revving, high performance motors. I ran 5W30 in my Denali/TB and the V I have owned in temperatures above 110 going uphill with the A/C blowing cold air in my face.

Racing is a different story.

[scjzman]

Stay with the 5W30 :yes:

[ScarabEpic22]

Stay with the 5W30 :yes:
Yea, definately.

You could run 10W-30, but then when winter came around you would want to switch back to 5W-30 as it can get cold in VA. I just run 5W-30 so I dont have to think about it at all.

[Rob]

The manual says 5w-30 is good for temps from below 0 to above 100 degrees, and that 10w-30 is acceptable above 0 degrees. It specifically says not to use 10w-40 or 20w-50. I'd stick to the recommendations. If you're concerned about getting the best protection for your engine, switch to synthetics.:)

[tblazed]

How can they say "preferred" when they don't know what the temperature is like where the car is?

The owner's manual says, use 5W-30 if ambient temps are going to be -20°F or higher, and you can use 10W-30 if temps are 0°F and higher, and straight 30W if above 32°F. Below -20°F a 5W-30 synthetic or a 0W-30 is recommended.


The higher "30" number refers to how the oil performs hot, so any of these should perform pretty much equally when the engine is at operating temp.

And yes, the cam actuator solenoid and phaser can be effected by oil. If it's too thick (like 20W-50) it can cause sluggish or poor response, and possibly set a DTC.

[Spong]

20w-50! I used to run that in my diesel!

Man, I'd would get that tar out of it ASAP.

I run 5w-30 year around and we can be -20 or like today, 105.

[Rob]

I used to have an '84 Dodge Daytona turbo that I ran Penzoil 20w-50 GT Performance oil in until one day in January when it was -2 degrees fahrenheit. Coldest I think it's ever been in Virginia Beach. No way that damn thing was going to start. Wouldn't hardly even crank. I was about 25, i.e. young and stupid.

[ylab]

The 5w30 will be just fine....Hell, Ford is now recommending 0w20 on many of their newer models! The thinner oil allows it to get in and lubricate places the thicker stuff may leave dry. With the newer oil technology, oils don't coke up like days of old. If you want more severe heat protection, you could always run a synthetic blend or full synthetic which would provide better protection against severe heat.

[MTPockets]

You could probably run anything from a 0w-20 to a 20w-50 and be perfectly fine with the 4.2L, depending on your conditions. I don't see the point in going more viscous than a 30wt on them with the 7qt sump.:confused: Plus a zillion GM's have lived long and happy lives the past 20yrs running run of the mill 5w-30's. 0w-30, 5w-30 and 10w-30 are all the same 'weight' once they reach normal operating temps (a 30wt). I dont see the point in 10w-30 anymore. The "less viscosity improvers in 10w-30" is a non issue now. 5w-30 is cheap and the most easy to get. May as well stick with it.

G/luck
Joel

[Stan]

I now see that all Mercedes are now factory filled with Mobil-1. What surprised me is vicosity. They are using 0-40 w. Average drain interval- ... also surprising... 15,000 to 20,000 milles.
I have seen some reports questioning Ford's use of a 5-20 weight oil and some oil related failure, a report I cannot seem to find.
Another odd thing... all oil removed via dipstick and not from the pan drain.

[MTPockets]

Yep, some of the new super fancy MB's don't even have an engine oil dipstick! You go by an oil level indicator.:crazy: I suppose if you can afford one, dealer service is a non-issue for you. Some new audi's and vee-dub's spec a 0w-40 or 5w-40 at a 10-15Kmi oil change interval. Most have gone back to a drop in oil filter cartridge as well.:rolleyes:

Joel

[Spong]

Some GMs have gone back to drop in oil filters.

[MTPockets]

Some GMs have gone back to drop in oil filters.

Yep, the 2.2 ecotec (baby 4.2L :D ) uses a drop in cartridge. You'd think they would be cheaper (less parts), but they cost more than a good spin-on filter!

Joel

[Spong]

I knew some cars had it but didn't know which ones.

[gmcman]

Your engine will run with 20W-50, but it is not designed for your application. That oil doesn't flow like the 5 or 10W-30 and the tighter clearances in the newer engines like more flow. 20W-50 is designed for engines commonly exceeding 220 deg oil temps or turbo engines, etc. You gain nothing by using it, probably dropping a little bit in the MPG game. Take a coffee filter and pour some 5-30 and 20-50 side-by-side into a container and see what you want trying to push through the tiny passages in your crankshaft.

[Str8blazin]

Thank you all for your help. I'm going to change the oil tomorrow and go with Mobile1 5w-30. I noticed a slight lose of power when I changed it. Thats what made me think about the Camshaft Position Actuator Solenoid. Thanks again! :)

[Spong]

Thank you all for your help. I'm going to change the oil tomorrow and go with Mobile1 5w-30. I noticed a slight lose of power when I changed it. Thats what made me think about the Camshaft Position Actuator Solenoid. Thanks again! :)

You're welcome to run 20w-50 in your minivan if you don't like the slick feel of synthetic 5w-30. :p :D

[steviestyles]

I'm amazed after reading this thread. My TB has written all over the Oil Cap....USE 5W-30 only, as well as in the manual. Maybe mine's unique.:weird:

[tblazed]

I noticed a slight lose of power when I changed it. Thats what made me think about the Camshaft Position Actuator Solenoid. Thanks again! :)


Thick, wrong viscosity oil is mentioned as a possible cause of a cam actuator problem in the service manual in the troubleshooting section, so you were on the right track.

BTW there is a difference in viscosities between 5w-30 and 10w-30 on the hot 100°c 30 weight side, not all the same when they get hot.They will still be within the 30w spec (9.3 to 12.5 cSt) for a 30 weight oil. A 10w-30 will have a slightly higher viscosity that a 5w-30, including Mobil 1, but will still be within the 30 weight window.

[Spong]

I'm amazed after reading this thread. My TB has written all over the Oil Cap....USE 5W-30 only, as well as in the manual. Maybe mine's unique.:weird:

:iagree:

Sometimes reading > People

[steviestyles]

:iagree:

Sometimes reading > People


lol.....:rotfl:

[BigJohnAZ]

A link to read and think about...

http://articles.mbz.org/oil/cu/

:undecided