10W30 vs. 10W40 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

joelboxt · 04-17-2005, 05:51 PM

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 · 04-17-2005, 06:17 PM

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 · 04-17-2005, 06:32 PM

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 · 04-17-2005, 06:41 PM

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

JimKshortstep4x4 · 04-17-2005, 07:49 PM

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 · 04-17-2005, 08:32 PM

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 · 04-17-2005, 08:45 PM

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

joelboxt · 04-17-2005, 08:46 PM

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

joel

joelboxt · 04-17-2005, 08:47 PM

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

JimKshortstep4x4 · 04-18-2005, 06:40 AM

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 · 04-18-2005, 07:16 AM

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

71-longbed · 04-18-2005, 07:52 AM

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 · 04-18-2005, 09:15 AM

Quote:

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 · 04-18-2005, 10:08 AM

Quote:

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 · 04-18-2005, 12:36 PM

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 · 04-18-2005, 01:17 PM

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 · 04-18-2005, 10:51 PM

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 · 04-18-2005, 11:12 PM

interesting!

71-longbed · 04-19-2005, 03:55 AM

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 · 04-19-2005, 06:50 AM

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

04-17-2005, 05:51 PM	#1
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	10W30 vs. 10W40 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 __________________ Last edited by joelboxt; 04-17-2005 at 05:51 PM.

04-17-2005, 06:32 PM	#3
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	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. __________________ Fred There is no such thing as too much cam...just not enough engine.

04-17-2005, 06:41 PM	#4
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	so 10W40 is ok for an oil change or two? __________________

04-17-2005, 08:45 PM	#7
kaycee Registered User Join Date: Jan 2000 Location: Wyoming USA Posts: 2,445	I run it all the time no problems here allso run AC/Delco filters __________________ 2001 Silverado K-1500 2005 FXDWG stage3 69 CHEVY Short/Step 327/4L60 373 posi 63 IMPALA 327

04-17-2005, 08:46 PM	#8
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	thanks for your input Jim, i was thinking the same thing to longhorn about those frams. i dont like them either. joel __________________

04-17-2005, 06:17 PM	#2
dropped_71chevy Registered User Join Date: Sep 2002 Location: Northern Colorado Posts: 198	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

04-17-2005, 07:49 PM	#5
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	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

04-17-2005, 08:32 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	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.

04-17-2005, 08:47 PM	#9
joelboxt 71 Cheyenne SWB Fleetside Join Date: Jan 2005 Location: Sarnia, Ontario, Canada Posts: 403	i run Delco filters also Kaycee, i think there a good choice __________________

04-18-2005, 06:40 AM	#10
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	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

04-18-2005, 07:16 AM	#11
70c10 67-72 Addict! Join Date: Feb 2002 Location: The TAX State! Posts: 7,857	I have never had a problem with Fram. I used a Purolator for my last oil change though. __________________ Jim 1970 C/10 Fleetside w/Ghost Flames Lowered 4.5" front and 4" rear (Raked) 355/350 Turbo w/shift kit 10" Redneck Performance Verter w/2500 stall Hooker Super Comps part#2808-1 Performer RPM Air-Gap 12 Bolt w/3:73 gears- Eaton Posi Comp Cams XE262 with 1.6 Crane Energizers, Road Demon 625 and Brodix IK 180 heads

04-18-2005, 07:52 AM	#12
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	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 ... __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

04-18-2005, 12:36 PM	#15
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	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

04-18-2005, 01:17 PM	#16
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	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 __________________ Fred There is no such thing as too much cam...just not enough engine.

04-18-2005, 10:51 PM	#17
booth Active Member Join Date: Feb 2003 Location: Lonsdale, MN Posts: 109	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 __________________ '67 Chevy LWB (Running) '67 Chevy LWB (Not Running) '70 Chevy LWB (In Pieces) '72 Chevy LWB (In Pieces)



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04-18-2005, 11:12 PM	#18
FirstGen Just Don't Stop! Join Date: Feb 2004 Location: Dallas Posts: 1,239	interesting! __________________ 1968 C10 build in process TT LSA/6L90e/9"

04-19-2005, 03:55 AM	#19
71-longbed Its Magically Delicious Join Date: Jan 2003 Location: oregon Posts: 2,398	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 .... __________________ 71 C10 LWB 350sbc -TH350 12 bolt 3.42 Posi Of all my favorite things to do, The utmost is to have a brew. My love grows for my foamy friend, with each thirst-quenching elbow bend. Beer so frosty, smooth, and cold it's paradise pure liquid gold. Yes beer means many things to me that's all for now cus I gotta pee.

04-19-2005, 06:50 AM	#20
booth Active Member Join Date: Feb 2003 Location: Lonsdale, MN Posts: 109	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 __________________ '67 Chevy LWB (Running) '67 Chevy LWB (Not Running) '70 Chevy LWB (In Pieces) '72 Chevy LWB (In Pieces)

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