Not Logged In Log In   Sign Up   Points Leaders
Follow Us    2:04 AM

Message Forum - Read Message

Category: Fuel Economy > Topics Add to favorite topics   Post new topicPost New Topic
Author Topic: Oil weight and gas milage Back to Topics
I_had_gas

Rookie Author
Bridgeport

Posts:18
Points:3,675
Joined:Jun 2013
Message Posted: Jun 4, 2013 2:02:33 AM

Does the weight (viscosity) of the oil you use affect gas mileage?
REPLIES (newest first) Post a Reply
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Aug 7, 2013 10:12:51 AM

"No"

Well you are wrong.
I have read technical papers published by Man diesel showing a 3% fuel economy difference between 5w-20 weight oil versus traditional 15w-40 weight oil and a 1% difference between 5w-20 weight versus 10w-30 weight oil.
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,457
Points:59,925
Joined:Aug 2009
Message Posted: Aug 7, 2013 9:40:37 AM

How about the old timers who thinned their oil for Winter with added kerosene Like "guess that ole do it" and save that carnation can of milk for the radiator leak when I put in the alcohol for Winter "Dearee".....
Profile Pic
hoopitup2000
Champion Author Virginia

Posts:1,357
Points:429,050
Joined:Jul 2013
Message Posted: Aug 7, 2013 6:47:23 AM

No
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Aug 7, 2013 3:45:53 AM

I found some quakerstate "advanced durability" 20w-50 weight oil on clearance at wallmart for $3/qt.

I grabbed a quart of 20w-50 weight oil in one hand and a quart of 5w-20 oil in the other and shook them both. The 20w-50 weight oil is like molasses and the 5w-20 weight oil sounds like a bottle of water.

I don't see anyone referring to their 5w-20 weight oil as advanced durability.
Profile Pic
Sipusa
All-Star Author Sacramento

Posts:726
Points:181,560
Joined:Mar 2011
Message Posted: Jul 29, 2013 11:59:01 AM

nope
Profile Pic
WES03
Champion Author Maryland

Posts:6,932
Points:1,748,515
Joined:Feb 2009
Message Posted: Jul 29, 2013 8:44:00 AM

Back in the day it did, but with today's 5W-20 used in many vehicles....no.
Profile Pic
kellyoneal
Champion Author Louisville

Posts:3,102
Points:1,200,590
Joined:Mar 2011
Message Posted: Jul 28, 2013 1:05:04 PM

no
Profile Pic
pt1KY
Champion Author Lexington

Posts:2,035
Points:494,440
Joined:Jun 2013
Message Posted: Jul 28, 2013 10:05:45 AM

Stick with manu. recommendation
Profile Pic
dv8jane
Veteran Author Chicago

Posts:301
Points:142,400
Joined:Mar 2012
Message Posted: Jul 20, 2013 12:41:46 PM

what the manufacturer recommends.
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,106
Points:768,365
Joined:Sep 2003
Message Posted: Jul 20, 2013 10:00:03 AM

OCEANARCHER ask: Which are you more concerned about, mileage, or wear rate?
______
Why do you have choose between the two? You have have high mileage AND long engine life.

I have used a 5W50 oil in all my rides since 2001 and I have always gotten about 25-30% more mileage than the EPA expectation. Though I have only about 55K on my engine, there is no indication whatever of any engine wear.

The thing to remember is that whether one uses a 5W50 or a 5W20 oil, Both should have reasonably similar performance at 0°C and that's where most engine wear occurs. At normal operating temperature, that 5W20 oil is effectively a 7 weight oil that I think is insufficient to protect an engine so I prefer a wider viscosity range oil.

[Edited by: Houckster at 7/20/2013 10:01:36 AM EST]
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jul 20, 2013 12:17:48 AM

"Which are you more concerned about, mileage, or wear rate?"

Both are very important considerations.
If I only cared about fuel economy I would use an oil that ends in 20.
Since I care more about the engine lasting I use oil that ends in 30 or 40.
Profile Pic
timewalker
Sophomore Author Indiana

Posts:176
Points:539,350
Joined:Aug 2011
Message Posted: Jul 19, 2013 6:08:31 PM

Likely what the manufacturer recommends, or better would be best.
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,106
Points:768,365
Joined:Sep 2003
Message Posted: Jul 19, 2013 4:13:27 PM

CARINTHUIST writes: Oil weight does effect gas mileage go with a synthetic blend for better gas mileage
______
Synthetic blends are usually 20% or less "synthetic" and the "synthetic" is probably petroleum. Who benefits: The retailer does since they can charge a higher price for something that costs them very little more. For the customer, there's almost no actual benefit.

Unless one wants to go to a true synthetic oil like SynLube, Amsoil Signature or Redline, it's just as well to buy a high quality Group II oil that meets the API SN or GM Dexos standard.
Profile Pic
giwan
Champion Author Michigan

Posts:1,599
Points:217,155
Joined:Aug 2009
Message Posted: Jul 19, 2013 12:10:30 PM

Yes of course. FRICTION
Profile Pic
MTK143
Veteran Author Pittsburgh

Posts:259
Points:88,635
Joined:Mar 2012
Message Posted: Jul 19, 2013 11:06:18 AM

no y would it
Profile Pic
carinthuist
Champion Author San Francisco

Posts:4,914
Points:837,525
Joined:Mar 2012
Message Posted: Jul 19, 2013 9:05:00 AM

Oil weight does effect gas mileage go with a synthetic blend for better gas mileage
Profile Pic
OceanArcher
Champion Author Mississippi

Posts:8,042
Points:1,872,725
Joined:May 2004
Message Posted: Jul 19, 2013 7:49:19 AM

Which are you more concerned about, mileage, or wear rate?
Profile Pic
FrankLee1
All-Star Author Minnesota

Posts:821
Points:35,000
Joined:Feb 2013
Message Posted: Jul 19, 2013 7:43:46 AM

"Oh let me guess, you think OEM knows best and that OEM has your best interests in mind, awww that's so cute." They do know, better than anyone else.

Who is "Cummings"? Remember, this is a family-oriented site.

[Edited by: FrankLee1 at 7/19/2013 7:44:53 AM EST]
Profile Pic
GLM4205
Champion Author Toledo

Posts:6,234
Points:1,301,590
Joined:Dec 2010
Message Posted: Jul 19, 2013 6:17:00 AM

It does.
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jul 17, 2013 2:23:46 AM

"which predicted 20 weight oil could do better in all ways for a bearing designed for 20 weight oil."

They are right, modern bearing design does well with thinner oil.
Bearing design 25 to 30 years ago sucked, that's all there is to it. No one used bearings that could handle 20 weight oil.
Do you know how they made bearings back then? I am guessing no.
They sprayed molten Lead alloy on the steel bearing halves.
Now OEMs use something like a tri metal build up, they use the steel backing plated with 3 softer metals. First layer over the steel is usually copper, then lead then something real soft like Tin and a polymer finish coat to top it off.
With tri metal bearings you can control the thickness of the bearings.

The thing with tri metal bearings is as long as the engine has the proper bearing clearances the Main, rod and cam bearing do well with pretty much any oil weight. So that's not the problem.
Cummins and Mann found most of the higher wear in the valve train parts. The problem was Steel pushing on steel not Iron or steel in light contact with softer bearing material.
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jul 17, 2013 1:39:24 AM

"That is not true. Engines which were designed for 20 weight oil will probably wear MORE with 30 weight."

Got any proof?
Oh let me guess, you think OEM knows best and that OEM has your best interests in mind, awww that's so cute.
Then why cant I find a study proving that thicker oil wears engines faster?
Mann and Cummings says thinner oil wears their engines faster.

All the real engines recommend oils that end in 30 or 40.

"If you say 30 weight is better then why not use 40? Or 50? Or just pump grease in your engine?"

I do, I use synthetic rotella 5w-40 in my diesel suburban, Camaro, I have used it in our Hyundai 3.3L V6.
In the summer I add a quart or 2 of mobil1 15w-50 oil to the 5w-40 normally in my diesel engine.

I have up to date technical manuals that recommend the use of straight out 30 weight oil in big diesel engines. These manuals warn that use of split weight oil causes faster engine wear.
Straight up 30 weight oil at room temperature is something like 70 weight.
Every thing I can find says thicker oil is better for preventing engine wear.
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,106
Points:768,365
Joined:Sep 2003
Message Posted: Jul 16, 2013 8:56:21 PM

GRUMPYKAT writes: That is not true. Engines which were designed for 20 weight oil will probably wear MORE with 30 weight.

About 25 years ago I was reading SAE journals about a breakthrough in the understanding of how motor oil protects, namely in plain bearings, which predicted 20 weight oil could do better in all ways for a bearing designed for 20 weight oil.

If you say 30 weight is better then why not use 40? Or 50? Or just pump grease in your engine?
______
That's what I did. I went from 5W20 to 5W50 and the engine ran great, didn't burn oil and would have lasted forever. Information you read 25 years ago is probably of little or no value today.

If you're going to contend that a 5W20 weight oil will protect better than a 5W30 or 5W40 oil, show some links that give substance to this claim. I'm willing to listen. I've looked for such articles and never found one to give substantive support to this proposition.
Profile Pic
GrumpyCat
Champion Author Alabama

Posts:5,275
Points:1,246,300
Joined:Jun 2009
Message Posted: Jul 16, 2013 3:35:25 PM

"Since there is only a 1% gain in fuel economy between 10w-30 and 0w-20. But that 1% increased fuel economy comes at the price of higher engine wear."

That is not true. Engines which were designed for 20 weight oil will probably wear MORE with 30 weight.

About 25 years ago I was reading SAE journals about a breakthrough in the understanding of how motor oil protects, namely in plain bearings, which predicted 20 weight oil could do better in all ways for a bearing designed for 20 weight oil.

If you say 30 weight is better then why not use 40? Or 50? Or just pump grease in your engine?
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jul 16, 2013 2:41:55 AM

Yes use 10w-30 oil.
Since there is only a 1% gain in fuel economy between 10w-30 and 0w-20. But that 1% increased fuel economy comes at the price of higher engine wear.
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,106
Points:768,365
Joined:Sep 2003
Message Posted: Jul 14, 2013 12:11:17 PM

In 2001, I bought a Ford Focus for which Ford recommended 5W20 oil. I switched to a 5W50 oil because I thought and still do think that these ultra thin oils are nuts. I never, ever got less than the EPA expected mileage. Usually I was 2-4 MPG above the expectation and it wasn't because I was such an efficient driver either. I wasn't doing much to avoid high fuel consumption like avoiding hard stops and starts.

My take on the 0W20 and 5W20 oils is that the OEMs get a bit better test results for their cars and that means that companies like Ford get to build more high profit trucks. They rationalize the use of 0W20 oil based on the knowledge that most engine wear occurs during cold starts. They expect that most oils will thicken as the miles add up and they want that oil to start circulating as quickly as possible. To get this advantage they are willing to tolerate increased engine wear when the engine is at normal temperature. That 0W20 weight oil is actually about 7 weight at 100° C.

Why they didn't specify oils that were better and provided excellent protection at all temperatures is anybody's guess but the cynic in me wants to believe that the OEMs have no interest in their cars and trucks lasting too long.

Whatever advantages are claimed for the low viscosity oils, I suspect are more than offset by increased oil consumption as the engine ages and by the increased maintenance required as the engine burns more oil which, of course, causes more pollution.

[Edited by: Houckster at 7/14/2013 12:14:25 PM EST]
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jul 14, 2013 11:10:32 AM

Oil weight does make a difference.

MAN diesel claims there is a 1% difference in fuel economy when going from 10w-30 weight oil to 0w-20 weight oil.
And that switching to 0w-20 from traditional 15w-40 oil offers a 3% savings.
but they also claim they saw higher rates of ware in certain engine parts.

I am going to stick with 10w-30 and 5w-40 for my diesel and gas engines.
Profile Pic
Mikeyl
Champion Author Cleveland

Posts:8,450
Points:1,743,930
Joined:Aug 2004
Message Posted: Jul 14, 2013 9:26:07 AM

I doubt it. When my oil change place switched me from 10W40 to 10W30 I didn't see any difference.
Profile Pic
PassmyGas
All-Star Author North Carolina

Posts:880
Points:769,380
Joined:Jul 2010
Message Posted: Jul 6, 2013 10:27:53 AM

very little!
Profile Pic
dontuknowOH
Champion Author Ohio

Posts:3,457
Points:59,925
Joined:Aug 2009
Message Posted: Jun 30, 2013 2:01:12 AM

I just stay with the recommended 5 W-30, 10 W-40, and summer 20 W-50, the Starter and engine crank speed during cold seasons can be affected when changing from the recommended weights then relating to other problems.
Profile Pic
duybn
Champion Author Connecticut

Posts:2,173
Points:538,080
Joined:Apr 2011
Message Posted: Jun 30, 2013 1:24:04 AM

No it doesn't, that depends on your foot. However, it MAY affect your Horsepower and/or ft/lb Torque but depends on the motor..et cetera. But overall, if it's not broke don't fix it.
Profile Pic
Dennis783
Champion Author Des Moines

Posts:16,065
Points:3,253,745
Joined:Sep 2005
Message Posted: Jun 28, 2013 7:19:11 AM

not really
Profile Pic
hyeglenn
Champion Author Fresno

Posts:3,363
Points:1,161,720
Joined:Apr 2011
Message Posted: Jun 27, 2013 11:42:22 PM

No.
Profile Pic
MertieMan
Champion Author Lexington

Posts:17,274
Points:3,470,535
Joined:May 2005
Message Posted: Jun 18, 2013 9:19:56 AM

It shouldn't affect it that much if you run what the manufacturer recommends.
Profile Pic
Jmac2008
Champion Author Missouri

Posts:4,391
Points:1,399,770
Joined:Dec 2008
Message Posted: Jun 18, 2013 1:09:08 AM

just use what your car manufacturer recommends.
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jun 17, 2013 10:36:42 PM

"The OEMs spec 0W20 for their benefit, not the customers"

Yes very true, you sir understand how it works.
I have read test by engine manufactures that showed increased engine wear on certain parts with 0w-20 oil compared to traditional 10w-30 weight oil.
Plus the fuel economy difference between 0w-20 Vs. 10w-30 is just under 1%.
Profile Pic
Houckster
Champion Author Atlanta

Posts:11,106
Points:768,365
Joined:Sep 2003
Message Posted: Jun 17, 2013 10:06:12 PM

The OEMs spec 0W20 for their benefit, not the customers. The minimum viscosity I'd use in an engine is a 0W30 or 5W30 true synthetic oil.
Profile Pic
contiki
Champion Author Ontario

Posts:25,723
Points:1,076,865
Joined:Sep 2008
Message Posted: Jun 17, 2013 8:32:48 PM

Use Honda oil only for our Honda vehicles........

Get oil changed at dealership on both Honda vehicles......
Profile Pic
ozziebaby
Rookie Author Michigan

Posts:34
Points:18,955
Joined:Jun 2013
Message Posted: Jun 17, 2013 7:04:55 PM

im thinking it does . my husband went to a synthetic oil in my 1 vehicle which improved mileage and performance
Profile Pic
GrumpyCat
Champion Author Alabama

Posts:5,275
Points:1,246,300
Joined:Jun 2009
Message Posted: Jun 17, 2013 2:39:33 PM

""A lot of the new cars are using a synthetic 0W20 oil. That being said stick with what the manufacturer recommends or you risk potential engine damage"

I wouldn't put it in a engine that had well over 100k miles on it."

If I had a 100k mile engine which specified 0W-20 when new I'd still put 0W-20 in it.

100k miles is *nothing*.
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jun 17, 2013 2:03:25 PM

"A lot of the new cars are using a synthetic 0W20 oil. That being said stick with what the manufacturer recommends or you risk potential engine damage"

I wouldn't put it in a engine that had well over 100k miles on it.
Profile Pic
jl1rp
Champion Author New Hampshire

Posts:4,540
Points:930,480
Joined:May 2012
Message Posted: Jun 17, 2013 10:55:57 AM

Yes but stay in the recommended weight ranges for your car's engine.
Profile Pic
speedy700
Champion Author New Jersey

Posts:2,871
Points:699,975
Joined:Jan 2013
Message Posted: Jun 17, 2013 8:58:08 AM

Yes, it does. A lot of the new cars are using a synthetic 0W20 oil. That being said stick with what the manufacturer recommends or you risk potential engine damage
Profile Pic
WES03
Champion Author Maryland

Posts:6,932
Points:1,748,515
Joined:Feb 2009
Message Posted: Jun 17, 2013 8:33:25 AM

Less resistance of any kind increases gas milage.
Profile Pic
dassfg
Champion Author Fort Worth

Posts:2,271
Points:1,043,620
Joined:Mar 2011
Message Posted: Jun 13, 2013 11:18:32 AM

Yes -- that is why the manufacture makes you use the recommended weight to avoid voiding the warranty
Profile Pic
33gort33
Champion Author Indiana

Posts:1,604
Points:643,760
Joined:Mar 2012
Message Posted: Jun 10, 2013 6:30:17 AM

yes, it does...but it hasta do a lot more then it used too.

not only lubricating but to diffuse heat buildup that the higher revving

smaller displacement motors give off.

Smaller motors work harder keeping you at speed, even with specific gearing.

Use the recommended OEM oil weight for the type of driving and the season you

are currently involved in...that'll will protect your investment in and

still return you with the best protection and mileage.
Profile Pic
xfatman
Champion Author Missouri

Posts:10,475
Points:2,562,495
Joined:Aug 2006
Message Posted: Jun 10, 2013 1:35:11 AM

stick to the manufactures recommendation.
Profile Pic
giwan
Champion Author Michigan

Posts:1,599
Points:217,155
Joined:Aug 2009
Message Posted: Jun 10, 2013 12:58:40 AM

it does
Profile Pic
oilpan4
Champion Author Virginia

Posts:13,545
Points:330,430
Joined:Jul 2006
Message Posted: Jun 7, 2013 12:26:27 PM

"Sounds like a test for "The MythBusters" television show"
No need its already been tested and confirmed by real scientists with a lab already setup to do these kinds of tests.

MAN diesel claims there is a 1% difference in fuel economy when going from 10w-30 weight oil to 0w-20 weight oil.
And that switching to 0w-20 from traditional 15w-40 oil offers a 3% savings.
but they also claim they saw higher rates of ware in certain engine parts.

I am going to stick with 10w-30 and 5w-40 for my diesel and gas engines.
Profile Pic
Dennis783
Champion Author Des Moines

Posts:16,065
Points:3,253,745
Joined:Sep 2005
Message Posted: Jun 7, 2013 7:43:32 AM

even if it did, its not worth messing with critical engine parts
Profile Pic
WEPSMAN
Champion Author South Dakota

Posts:11,296
Points:2,533,125
Joined:Mar 2005
Message Posted: Jun 5, 2013 9:16:08 PM

It will have some affect on it, but probably not noticeable. You might notice heavy oil in cold weather make more of a difference.
Post a reply Back to Topics