Best weight oil for my S-10 truck?

[Electric Amish]

Stupid thing didn't come with a manual.

What weigth do you guys think is best?

V6 engine, '94

 

[Quixfire]

5W30 is what I believe the factory recommends.

But some will differ with that statement.

 

[DurocShark]

I use 10w30 in my 96 4cyl in the winter and 10w40 in the summer...

140k miles, running perfect.

 

[waitman]

Originally posted by: Quixfire
5W30 is what I believe the factory recommends.

But some will differ with that statement.

I had one of those and somewhere under the hood it said 5w30.

 

[NikPreviousAcct]

I have an '85 S-10 Blazer with a 2.8L V6. In the summer, I use 10w40. In the winter, I use 10w30.


<edit> I'm an idiot.

 

[lowtech1]

Originally posted by: Electric Amish
Stupid thing didn't come with a manual.

What weigth do you guys think is best?

V6 engine, '94

It all depend on how much oil are you losing. But, the common recommended oil is 10-30. You can also use 15-40 for the summer and that should be fine to, or if your engine is losing oil too quickly.

 

[Vette73]

Use 10W30 year round, UNLESS it get REALLY cold where you live.

I prefer Mobil myself, but don't use Fram oil filters.

 

[Electric Amish]

Originally posted by: lowtech

Originally posted by: Electric Amish
Stupid thing didn't come with a manual.

What weigth do you guys think is best?

V6 engine, '94

It all depend on how much oil are you losing. But, the common recommended oil is 10-30. You can also use 15-40 for the summer and that should be fine to, or if your engine is losing oil too quickly.

Not losing any oil AFAIK. Just wanted to have some on-hand and getting the info prior to a change.

Thanks all.

 

[Electric Amish]

Originally posted by: Marlin1975
Use 10W30 year round, UNLESS it get REALLY cold where you live.

I prefer Mobil myself, but don't use Fram oil filters.

What's "Really" cold? Gets in the teens here in Utah during the winter usually, and sometimes lower.

 

[Vette73]

Originally posted by: Electric Amish

Originally posted by: Marlin1975
Use 10W30 year round, UNLESS it get REALLY cold where you live.

I prefer Mobil myself, but don't use Fram oil filters.

What's "Really" cold? Gets in the teens here in Utah during the winter usually, and sometimes lower.

If it gets in the low teens then 5W30 in the winter will be better.

 

[Quixfire]

Here is some information from Quaker State's Website on how to choose the correct viscosity of oil.

Myth #8
Heavier is better.
Thicker is better.
You can tell the viscosity of oil by feel (between your thumb and fore finger).
?I?ve used straight 30 weight for years.?
Motor oil viscosity is not that big a deal.
Thicker motor oil is better for your engine and increases engine life.
One must use SAE 20W-50 motor oil if the vehicle has over 100,000 miles on it.
SAE 5W-20 is too thin to protect the engine.
Synthetic SAE 5W-30 is thinner than conventional SAE 5W-30 motor oil.
Straight weight oils (i.e., SAE 30) give better protection than multi-viscosity oils.

Fact
There are two main reasons why vehicle manufacturers recommend thinner or lighter viscosity grades of motor oil. First, a gain in fuel economy can be achieved with lower viscosity oil. At cold temperatures and at start up, lower viscosity oil will reduce internal engine friction. About 10% of the engine's horsepower is lost to internal engine friction, resulting in a drop in fuel economy. Additionally, vehicle manufacturers are struggling to meet Corporate Average Fuel Economy (CAFE) requirements set by the government and avoid paying associated fines. Any fuel mileage improvement associated with a lubricant use would be good for them, and lighter viscosity grade motor oil will make a difference.

Second, thinner motor oil is essential for easy starting, particularly in cold weather, and for proper lubrication once the engine starts. Today's smaller engines have smaller clearances and tighter tolerances between moving parts, and there have been some instances where camshaft damage has occurred because of inadequate lubrication with higher viscosity grades in colder weather. Thinner oils, such as SAE 5W-30, will flow faster than heavier motor oils during start-up and initial engine operation and will help protect the engine from excessive wear. Multigrade oil will also offer the same high temperature protection as single grade motor oil. Always check your vehicle owner's manual to select the proper viscosity grade based on the expected temperature range.

The viscosity grade(s) recommended by the vehicle manufacturer depend somewhat on engine design. Engine manufacturers have spent considerable time and expense experimenting with different viscosity grades and have indicated in the owner's manual the grades they feel will best protect the engine at specific temperatures. While one manufacturer's engine may require an SAE 10W-30, another manufacturer's engine may require an SAE 5W-20 viscosity grade. This is likely due to different tolerances within the engine or other engine design factors.

 

[WhiteKnight77]

Use what the manufacturer of the vehicle states. With clearances measured in the .0001" range for some engines (some main bearing journals are ground to .002"+- .0001" oil clearance), trying to shove a 10W40 or heavier thru it specially when cold (when you first start the car in the morning or after all day at work no matter what the outside temp) will tear up the bearings after a while.

Some of you may have had a Ford Contour that burned up valves. Ford would not warranty the heads if the oil was found to be the wrong viscosity. This applied to the 2.0L engine and not the 2.5L V6. Seems the oil wouldn't bleed out of the lifters and when the car was restarted, the valves burned up (they didn't burn up overnight.) Fords from 2000 on now state on the oil fill cap in yellow letters 5W20.

Most manufacturers recommend 5W30 nowadays though Caddies with the Northstar V8 take 10W30. Check the manual for more info on what it takes. If all else fails, there is a lable under the hood somewhere that may (Fords do along with most Asian makes) that will tell you what to use.