10W30 vs. 10W40

[joelboxt]

hey whats the differance? got my girl friend to pick up some valvoline oil for me. i asked for 10W30 and she brought home 10W40.. is that ok to toss into the engine? its a 350CI.

its 10 weight 40 viscosity right? so is 30 tinner then 40?

thanks


joel

[dropped_71chevy]

Oil Viscosity
The viscosity of multi-weight motor oil is specified using two numbers. The first number is the viscosity when the oil is cold. This is followed by the letter W (which stands for winter, not weight), which is followed by the number that indicates the viscosity when the oil is at operating temperature. The higher the number the thicker the oil.

i got this from http://www.nordicgroup.us/oil.htm#Th...%20Mile%20Myth

there's some other good info on that link also

[Fred T]

Problem with 10W-40 is that it uses a lot more polymers to maintain the viscosity spread, and the more polymers the more chance of oil breakdown. 10W-40 has improved over what it was in the 70s, but it's still not as good as the 10W-30.

That said, I wouldn't be afraid to use it for one oil change, I just wouldn't make a habit of using it. The most important thing is to change the oil.

[joelboxt]

so 10W40 is ok for an oil change or two?

[JimKshortstep4x4]

I use 10w40 for all of my vehicles. I have a 95 Escort with the original engine in it which has 324,000 miles on it. I change oil and filter every 5,000 miles and use Valvoline 10w40 with a Fram filter. The engine still does not use oil and my contention is if there were anything seriously wrong with 10w40 the engine would have expired long time ago.

When we ran viscosity tests on oil in our Physics class we could not measure the difference in viscosity comparing oil with a viscosity of 5 against an oil with a viscosity of 40. This test was done with oil at 200 degrees F using a viscometer.

I run 10w40 because the way I drive the car, (mostly high way miles) so the engine is warm most of the time it is run.

Jim

[Longhorn Man]

Jim, you do know that fram has one of the worst filters on the market right?
Obviously, it still works, but it barely meets OEM required levels.

[kaycee]

I run it all the time no problems here allso run AC/Delco filters

[joelboxt]

thanks for your input Jim, i was thinking the same thing to longhorn about those frams. i dont like them either.


joel

[joelboxt]

i run Delco filters also Kaycee, i think there a good choice

[JimKshortstep4x4]

Longhorn,

I have heard about the Fram filter issue and have not seen any problems with them. I have used Frams for a very long time in lots of different cars. What ever the problem is, it has not shown up for me.

Do you have the documentation on why they are bad? I would really like to see it.

Jim

[70c10]

I have never had a problem with Fram. I used a Purolator for my last oil change though.

[71-longbed]

i recently switched from 10w40 to 10w30 ... but i make lots of short trips .. and my oil gets changed at about 2,000 miles .. oil is cheap so i'd rather change it often then run into problems ... I'm running ac delco duraguard silvers ... ac delco discontinued the filter but i found a box of 6 on evilbay for cheap ... they have a lower micron rating then the regular duragaurd ...

[RainFade]

Originally Posted by JimKshortstep4x4

Longhorn,

I have heard about the Fram filter issue and have not seen any problems with them. I have used Frams for a very long time in lots of different cars. What ever the problem is, it has not shown up for me.

Do you have the documentation on why they are bad? I would really like to see it.

Jim

I have definitely noticed noiser lifters at startup on fram filters and not just on sbc but on my fords and even import stuff.
Hadn't made the connection until I saw that guys comparison where he cut apart about every filter know to man for a 5.0 (just the application he chose) and he commented on the lousy fit and finish of their anti drainback valves.
Switched to the premium napa filter on all my stuff and immediately noticed quieter starts, and I'm pretty sure it is not the placebo effect in action

[mrein3]

Originally Posted by JimKshortstep4x4

I use 10w40 for all of my vehicles. I have a 95 Escort with the original engine in it which has 324,000 miles on it. I change oil and filter every 5,000 miles and use Valvoline 10w40 with a Fram filter. The engine still does not use oil and my contention is if there were anything seriously wrong with 10w40 the engine would have expired long time ago.

That is good to know. I'm at 226,000 and counting in my 94 Escort.

In my new cars I use what the manufacturer suggests. On the 94 Escort it is 5-30 winter and summer. In the 98 Explorer it is 5-30. In the 04 Explorer Ford specified 5-20. So I use that year round.

In old older stuff I use 10-30 winter or summer. However for years I ran 10-40 in the summer and 10-30 in the winter because my Dad did. I've owned the 72 Chevelle long enough to have had to keep a can spout in the garage. I'm sure that can of 10-40 is nothing compared to today's 10-40 so I think you'll be ok with a load or two of 10-40 in the summer.

BTW, it is rare but some days my Escort has to start when the ambient temperature is -30 Fahrenheit in the winter and +100 F in the summer. The oil I dumped yesterday had a -20F start and a +70F start on the same 4 quarts of 5-30.

[JimKshortstep4x4]

merin3

We rarely see temperatures down to 10 degrees F. If we did I would go to a lighter grade in the winter. I get cold just thinking about -30!

Jim

[Fred T]

Here's the oil filter study most go to for info. Info is now 2 years old, and manufacturers do make changes.
http://minimopar.knizefamily.net/oilfilterstudy.html

[booth]

72-longbed,
I would like to try and talk you out of replacing your oil every 2000 miles.

Yes oil is cheap, so are filters. If you were going to change anything @ 2000 miles it should be your oil filter, maybe. Take your favorite brand of oil new in the quart bottle, I don't care if it's synthetic or not. Send the whole bottle in for analysis, they won't use very much of that quart but it saves you from containinating the oil by just taking a sample and sending it in. I can guarantee you that the partical size and weight distribution is at least twice as high as the car manufacture recomends. Now lets say you take it out of a 55gal drum. That puts another wrinkle into the equation. Not only are these drums notoriosly dirty, what happens when you take a gallon and a half out of that 55gal drum, let it sit next to your garage door where the temperature is not steady. You will start to build up moisture, now your next oil change comes around and you take a gallon and a half out of that drum. You have now not only injected more dirt into your clean engine from that dirty drum you have also added water into your system which really gums up the mix. What I'm saying is if you change your oil every 2000 miles your just increaseing the dirt ingress into your engine.

I would like to invite everyone that has questions about there filters to cut them apart. Find out whats inside. Look at the endcaps and the media, count the number of pleats.

Now remember a good quality air cleaner and breather is your number one offence against a contaminated engine. If built right, a gasoline engine will not produce as much contaiminate from the combustion cycle as a poorly designed poorly maintained far to open air filter will.

Oil filters and particularly air filters get more efficient over time its called loading as the particals collect on the top of the media it blinds off the holes not allowing more dirt to pass through. This also means that the preasure it takes to push the air or oil through the media has increased also this is called pressure drop.

I'm done rambling for the night this is a subject that hits pretty close to home. Sorry about my poor spelling.

Later,
Paul

[FirstGen]

interesting!

[71-longbed]

booth ... 71-longbed not 72-longbed ... I dont understand why you would think changing your oil more often would be worse... i buy oil buy the quart ..so your drum theory doesn't pertain to my situation ... Its my understanding that heat is the biggest factor when it comes to oil and it's degrading nature ....

[booth]

Sorry 71-longbed,
What I'm trying to tell you, the new quarts bottles that you buy are not nearly as clean as they should be. All you are doing is injecting more and more contaminate into the system each time you change your oil. And by changing your oil in shorter intervels your not allowing the filter to do its job.

In a perfect world a you would filter your oil before your put it into your engine. But thats not always possible.

Later,
Paul