Is there that much of a difference in these (2) weights of oil? My 97 4.2V6 calls for 5W30 and I have been using 10W30 Chevron Supreme since I bought it used in Feb.02 with 64K miles,except for the last oil change which Ford did.I had my lower intake gaskets changed and they used 5W30 for the oil change.Also,I live in Tampa Florida so its warm here year round.Ide like to hear opinions,facts,suggestions,or whatever anyone knows about this subject.

 

for what it's worth...
My 2000 4.2 has lived on 10W-30 since its first oil change. It will hit 81,000 miles within a week or so. Ihave had zero issues of any sort with the 10W-30. I think 4 different oil analysis have all come back just fine. My OPINION is 10W-30 is probably the best all-around oil for those (like me -Alabama) who live in mild to moderate climats. Even then, I think those in extreme cold will be well served with a syntheic 10W-30.
ALl I have read seems to indicate the 5W-xx oils are primarily reccommended for CAFE reasons and not necessarily protection reason.

I might be wrong, but I'm sticking with the 10W-30.

Brian A

 

The biggest difference is when the engine is cold. That's where the 5w and 10w come into play. At operating temps the oils have the same viscosity as a 30 weight oil. Since you live in warm climate 10w30 is a fine choice.

 

[updated:LAST EDITED ON 26-Dec-02 AT 10:32 PM (EST)]As per usual - I agree w/ BrianA & rgiles - 100%!

PS - I think you've made an excellent choice in picking AND sticking w/ Chevron - and in Tampa, I'd use a 10w30 year round.

Tell us more about you're driving (conditions/service/duty/style) and we (or at least I) would be happy to make additional comments/suggestions. - Also, how many miles on the truck now, how often do you change the oil, and are there certain types of filters (oil AND AIR) that you tend to use?

Thanks - Glenn . . .

 

I just completed reading an article about this very subject. It went on to say that at -15C the 5-30 takes 10 seconds after start-up to reach the lifters and 40 seconds to flow freely. The 10-30 takes 20 seconds to reach the lifters and 3 minutes to flow freely. It also goes on to say that in warm climates the use of 5-30 has little significance vs. the 10-30. According to this the 10-30 would be a good choice in your application.

Randy

 

In moderate climate(above freezing) I think the only difference is the slight gas mileage advantage of 5W30 over the 10W30.

Like the guys say, in cold climate the 5W has the advantage.

I once used 20W50 dino and got hit with cold weather in New Mexico. I would guess it was in the teens to 20s above 0F. The engine was slow to crank and the radiator coolant(30af/70h2o) was slushy. The tranny stick moved like it was in putty(90W140 fluid).

So I guess that expereience told me that even above 0, thinner oil is an advantage for cold starts. Also looks like a higher concentration of antifreeze was in order. Course, now a days 50/50 coolant is recommended.

I now use synthetics exclusively in all my vehicles, so weight is almost a moot question. Temperature in the winter gets into the 20s and sometimes teens at night. I cannot tell any difference in cranking speed with 5W30 or 10W30 syn or even 0W30. Only difference I have noticed is that with 0W30 in summer, the engine makes more noise, so I don't use 0W30 at all, maybe Alaskans can use it.

Just my expereiences,

Jim Henderson

 

Pig Farmer Randy, point me to that article, please.

 

Well,I drive 50 miles round trip each day for work.It is all interstate so my speeds vary from 65-75mph.Sometimes towards the end of each week,traffic crawls thru downtown Tampa for like 3-5 miles.So,then my average speed is 5-25 mph.I currently have almost 82k miles on it.I was considering going to Mobil1 10W30.I also use Motorcraft #400S oil filters,and stock air filters.Oil changes every 3000 or 3 months.

 

skoop,

http://www.autosite.com/garage/encyclop/ency01s.asp Read on down and you'll find the segment that discusses this.

Randy

 

I suspect this info is bogus:
(copied and pasted from above link)
Refering to the Cold Cranking Simulator lab test:

"START QUOTE .... "With 10W oil, this is done at 20 deg. C., but with 5W, the temperature is 25 deg. C. The pumping test is a simulation of two parameters: Will it be picked up by the pump, and will it cavitate? This is checked at 25 for 10W, and minus 30 for 5W. There's a method to this madness. That five degree difference means that if an oil allows the engine to crank, there will be flow."

The lube chemist told me, "The lighter the oil, the less friction, which means better efficiency. Heat transfer is also a little better. At minus 15 deg., 5W30 takes 10 seconds to reach the rocker arms, compared to 20 seconds with 10W30. But the interesting thing is that 5W30 is flowing freely to the rockers in 40 seconds, whereas with 10W30 it takes three minutes! And it provides the same high-temperature protection as 10W30. The preferred oil in 86% of the new cars from Detroit is 5W30." END QUOTE

look close at the temps...
20 deg. C is about room temp! This is not "cold" as I think of cold.
It say: "25 for 10W and minus 30 for 5W". This is a 55 deg. C. differntial. Am I missing something here?
I might be worng but the whole comparison of times seems suspect.
10W30 takes 20 seconds to reach the rocker arms, but 3 minutes to flow freely. This just doesn't seem right. It just seems like it would not take an awful lot of ("cold") start ups to ruin the valve train at these times. In general, I'd not expect as much difference as is cited when comparing 5W and 10W.

I am open to being corrected. Comments please ???

Thanks a lot,
Brian A

 

--Yeah, Brian, I picked up on that, too. With the first quotation, I think that it's just poorly edited. I think that the word "minus" is missing in three places:

With 10W oil, this is done at HERE 20 deg. C., but with 5W, the temperature is AND HERE 25 deg. C. The pumping test is a simulation of two parameters: Will it be picked up by the pump, and will it cavitate? This is checked at AND HERE 25 for 10W, and minus 30 for 5W.

--Otherwise, it just doesn't make sense because, as you say, 20C° is downright balmy for a motor oil, and the range for comparison is too disparate between the two weights of oil.

--As for the other data regarding flow, I don't know. They don't feel right intuitively, but, at the same time, chemistry does that sometimes. I'm not familiar enough with oil chemistry to say that these are bogus data. They are suspect though, simply by virtue of the fact that the document appears not to have been proofread very well, or that it was transcribed inaccurately.

 

[updated:LAST EDITED ON 28-Dec-02 AT 02:11 PM (EST)]>I suspect this info is bogus:
>(copied and pasted from above link)
>Refering to the Cold Cranking Simulator lab test:
>
>"START QUOTE .... "With 10W oil, this is done at 20 deg. C.,
>but with 5W, the temperature is 25 deg. C. The pumping test
>is a simulation of two parameters: Will it be picked up by
>the pump, and will it cavitate? This is checked at 25 for
>10W, and minus 30 for 5W. There's a method to this madness.
>That five degree difference means that if an oil allows the
>engine to crank, there will be flow."

The above makes more sense when both are minus temperatures. I think that's what the article meant even though it wasn't very clear.

>The lube chemist told me, "The lighter the oil, the less
>friction, which means better efficiency. Heat transfer is
>also a little better. At minus 15 deg., 5W30 takes 10
>seconds to reach the rocker arms, compared to 20 seconds
>with 10W30. But the interesting thing is that 5W30 is
>flowing freely to the rockers in 40 seconds, whereas with
>10W30 it takes three minutes! And it provides the same
>high-temperature protection as 10W30. The preferred oil in
>86% of the new cars from Detroit is 5W30." END QUOTE

I don't know if the time is correct for getting to the lifters but I bet it isn't too far off. As far as the freely flowing times, I guess that depends on what they meant by freely flowing. I think the safe answer in these temps isn't 5w 10w, but rather an oil pan heater Now what protects the engine during this time? I would guess the oil film that is still on all parts, plus boundary protection offered by ZDDP and moly additives, or esters found in synthetics.

>look close at the temps...
>20 deg. C is about room temp! This is not "cold" as I think
>of cold.

They meant minus temps - poor writing on their part. I personally would use 5w30, 0w30 or 0w40 synthetic in really cold areas because they flow much better than conventional. If you have an oil pan heater, either dino or synth would be a safe bet.

Edit: Skoop sorry for being redundant, I must have been in the middle of replying when you posted

 

Great minds thinking alike.

 

You guys have eagle eyes!! I didn't pick up on the missing minus signs. I tend to scan read and saw the "minus 15 deg" part that caught my eye and then didn't bother to go back and re-read. After re-reading tho I'm sure the article meant negative numbers. Like guys said +20C is pretty balmy when it comes to testing flowability of oils.

Randy