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Reg Mauler
Premium Member
join:2004-01-06
Phoenix,AZ

Reg Mauler

Premium Member

[Help] 5w-20 vs 5w-30

Ok so here's the deal, we just got a new car (2007 Honda Accord SE 4 cyl) about a month ago and we are moving down to Phoenix in about a week. I want to change the oil before we go so I don't have to mess with it down there (just one less thing to worry about). My question is, the engine calls for 5w-20 but down there it is very hot so I was thinking of putting 5w-30 in it (synthetic of course). Will this be acceptable? I would usually just go with my gut on this sort of stuff as I'm usually pretty knowledgeable with things like this but I figured I would ask some of the people in here who may have more experience then me.

Cho Baka
MVM
join:2000-11-23
there

Cho Baka

MVM

I would imagine that 5w-30 would be fine, but I can't say that it would be necessary.

You could call a dealer down there and ask them what their summer fill is...
tcope
Premium Member
join:2003-05-07
Sandy, UT

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The weight you would be changing is the viscosity of the oil at normal operating temps. There is no reason for the temp of the oil to change in the engine (once hot) when the temp outside changes by 10 or 20 degrees (while still in the 80-110 range). It's the initial viscosity that would be effected, when the engine has not been warmed up.

Your vehicle should have a manual which should tell you what weight oil to use in different climate. I'd use their recommendation.

With that being said, I'd not change the weight of the oil.

rds24a
Teach Your Children
Premium Member
join:2000-12-13
Newton Upper Falls, MA

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The 5W is the only thing that would be affected by the ambient air temperature. The 30 part is at engine operating temperatures, which are much higher than I hope ambient air temperature ever gets. The engineers have taken into account variability in air temperature when designing the car, so do not vary from the manufacturer's recommended weight. Also note: some manufacturers are not recommending synthetic for brand new cars because it lubricates too well and does not allow for proper engine break-in. Double-check your manual on that issue, too.

Lurch77
Premium Member
join:2001-11-22
Green Bay, WI

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Either will work fine. I'd personally stick the 5w-20.

BusinessMan0
join:2007-05-17
Ontario, CA

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I use 5w-30 for both of my cars, which are less than 1 years old.
PrntRhd
Premium Member
join:2004-11-03
Fairfield, CA

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I use the manufacturer recommended weight, never had a lubrication issue, summer or winter.

Reg Mauler
Premium Member
join:2004-01-06
Phoenix,AZ

Reg Mauler

Premium Member

Ok I understand what you guys are saying. I was just worried about it being too thin at those temps, I was just down there and the heat is like nothing I've ever felt so I was worried about the oil basically turning into water as 20 weight is pretty thin and I read that the only reason they use it is to increase their fuel economy numbers. Oh and the car is plenty broken in, has close to 2k miles.

evergreek
Boeing Rocks
join:2003-05-25
Austin, TX

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I use 10w30 in my brand new 07 accord,, 5k miles.

rds24a
Teach Your Children
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join:2000-12-13
Newton Upper Falls, MA

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The ones I've seen, the break-in period is 10K.

WTF
@bellsouth.net

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Anon

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said by Reg Mauler:

Ok so here's the deal, we just got a new car (2007 Honda Accord SE 4 cyl) about a month ago and we are moving down to Phoenix in about a week. I want to change the oil before we go so I don't have to mess with it down there (just one less thing to worry about). My question is, the engine calls for 5w-20 but down there it is very hot so I was thinking of putting 5w-30 in it (synthetic of course). Will this be acceptable? I would usually just go with my gut on this sort of stuff as I'm usually pretty knowledgeable with things like this but I figured I would ask some of the people in here who may have more experience then me.
Consult your owner's manual, and use what it tells you to, based upon your climate. A 5W-20 will provide faster flow and superior lubrication (as in less time to achieve oil pressure) in cold weather. Also, the narrower weight gap (5W-20, as opposed to 5W-30) means that the oil is more stable in maintaining it's specified viscosity.

However, any oil's performance is optimized to a certain operating temperature range. A 5W-30 weight engine oil will be much better suited to higher temps, as in spring to summer weather conditions, whereas a 5W-20 oil is not designed to operate in those higher temps, and will break down and start to oxidize fairly quickly ( with the possible exception of a high-quality FULL synthetic oil). The reason for using a 5W-20 or 5W-30 in newer cars (as opposed to a 10W-30 is because in new engines, the critical internal clearances are much tighter (sometimes as tight as 2 to 5 ten-thousandths of an inch, or .0002-.0005).

The lighter viscosity oil will provide lubrication much quicker, and reduce contact wear considerably better than a 10W-30 oil. Overall, probably the best bet is to use a 5W-30 oil most of the time, because it is a wide range protection oil, and swith to the 5W-20 in much colder climates. As the engine accumulates mileage, you can think about switching to a 10W-30 to compensate for larger internal critical clearances due to normal operational wear, but know that increasing viscosity increases the time it take to achieve full oil pressure, thereby increasing initial start-up wear on all sleeve, non-roller bearings, and pushrod/rockers/cam lobes.

Sorry for being long-winded, but I hope this helps!

Reg Mauler
Premium Member
join:2004-01-06
Phoenix,AZ

Reg Mauler

Premium Member

said by WTF :
said by Reg Mauler:

Ok so here's the deal, we just got a new car (2007 Honda Accord SE 4 cyl) about a month ago and we are moving down to Phoenix in about a week. I want to change the oil before we go so I don't have to mess with it down there (just one less thing to worry about). My question is, the engine calls for 5w-20 but down there it is very hot so I was thinking of putting 5w-30 in it (synthetic of course). Will this be acceptable? I would usually just go with my gut on this sort of stuff as I'm usually pretty knowledgeable with things like this but I figured I would ask some of the people in here who may have more experience then me.
Consult your owner's manual, and use what it tells you to, based upon your climate. A 5W-20 will provide faster flow and superior lubrication (as in less time to achieve oil pressure) in cold weather. Also, the narrower weight gap (5W-20, as opposed to 5W-30) means that the oil is more stable in maintaining it's specified viscosity.

However, any oil's performance is optimized to a certain operating temperature range. A 5W-30 weight engine oil will be much better suited to higher temps, as in spring to summer weather conditions, whereas a 5W-20 oil is not designed to operate in those higher temps, and will break down and start to oxidize fairly quickly ( with the possible exception of a high-quality FULL synthetic oil). The reason for using a 5W-20 or 5W-30 in newer cars (as opposed to a 10W-30 is because in new engines, the critical internal clearances are much tighter (sometimes as tight as 2 to 5 ten-thousandths of an inch, or .0002-.0005).

The lighter viscosity oil will provide lubrication much quicker, and reduce contact wear considerably better than a 10W-30 oil. Overall, probably the best bet is to use a 5W-30 oil most of the time, because it is a wide range protection oil, and swith to the 5W-20 in much colder climates. As the engine accumulates mileage, you can think about switching to a 10W-30 to compensate for larger internal critical clearances due to normal operational wear, but know that increasing viscosity increases the time it take to achieve full oil pressure, thereby increasing initial start-up wear on all sleeve, non-roller bearings, and pushrod/rockers/cam lobes.

Sorry for being long-winded, but I hope this helps!
I pretty much knew that the start up viscosity would be about the same (that's what the 5 is). I was worried about it being too thin at those temps (and yes I know the engine operates at alot hotter temp then the ambient air temp but that doesn't mean the oil doesn't get hotter than that sitting 6 inches above the searing hot blacktop). So basically the debate comes down too 20 weight vs 30 weight.

mattmag

join:2000-04-09
NW Illinois

2 recommendations

mattmag

said by Reg Mauler:

So basically the debate comes down too 20 weight vs 30 weight.
Actually there should be no debate at all.

Follow the instructions in your owner's manual for the proper weight oil to use. There is much mis-information circulating about motor oil and what the viscosity specification truly means, and some of it has found its way into this thread.

Bottom line= do what the manufacturer says to do for your particular situation. You'll never go wrong.

-Matt

hayabusa3303
Over 200 mph
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join:2005-06-29
Florence, SC

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I agree with all who says do the owners manual.

Could be the reason Is this. 20 weight is much thinner at (high temps) vs 30 weight oil. Thinner the oil the more the oil can get to where it needs to go in the engine. Todays engines are getting smaller high Hp and at the same time smaller parts are in the engine.

Now with small parts in the engine thicker like the 30w might not get to where it needs to go like btw camchaft and valve. Using a thicker oil can reduce the valve opening. It does not sound like alot but to todays engine with very very close tolerance it doesnt take much.

Irun Man
Premium Member
join:2002-10-18
Millsboro, DE

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said by mattmag:
said by Reg Mauler:

So basically the debate comes down too 20 weight vs 30 weight.
Actually there should be no debate at all.

Follow the instructions in your owner's manual for the proper weight oil to use. There is much mis-information circulating about motor oil and what the viscosity specification truly means, and some of it has found its way into this thread.

Bottom line= do what the manufacturer says to do for your particular situation. You'll never go wrong.

-Matt
100% correct, great advice.

We have two 2006 Hondas (Accord and CR-V) with the same 2.4 liter L4 engine. The manual recommends 5W-20 oil, and we're NOT about to question the wisdom of a manufacturer with the reputation of reliability of Honda.

Also remember this... your vehicle is STILL UNDER WARRANTY. Changing to a different viscosity could affect your coverage. Don't experiment now. Dig a little deeper in your owner's manual and you'll read that Honda specifically recommends that you DO NOT change the oil for the first time until the maintenance reminder light comes on (my 2006 Accord's "wrench light" came on at exactly 6000 miles). Wait until at least that event to change the oil, topping off with Exxon Mobil 5W-20 dino oil which is what repackaged Honda motor oil is anyway.

footnote: We followed this advice to the letter, changing the oil @ 6000 miles in the Accord and 8000 miles in the CR-V. Both vehicles haven't burned any noticeable amount of oil since, so the break-in recommendation is spot on.

Reg Mauler
Premium Member
join:2004-01-06
Phoenix,AZ

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said by mattmag:
said by Reg Mauler:

So basically the debate comes down too 20 weight vs 30 weight.
Actually there should be no debate at all.

Follow the instructions in your owner's manual for the proper weight oil to use. There is much mis-information circulating about motor oil and what the viscosity specification truly means, and some of it has found its way into this thread.

Bottom line= do what the manufacturer says to do for your particular situation. You'll never go wrong.

-Matt
Ok I'll go quietly Thanks all!

Cho Baka
MVM
join:2000-11-23
there

Cho Baka

MVM

Have you looked in the manual?

Some of them have temperature dependant ranges that result in the vehicle having two specified acceptable viscosities.

What does the manual actually say?

WTF
@bellsouth.net

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Thers's no debate. Re-read the fist paragraph of my post.

Irun Man
Premium Member
join:2002-10-18
Millsboro, DE

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said by Cho Baka:

Have you looked in the manual?

Some of them have temperature dependant ranges that result in the vehicle having two specified acceptable viscosities.

What does the manual actually say?
This is quoted from the 2006 Accord owner's manual, page 204 under the heading Recommended Engine Oil (I expect the 2007 version to be identical or very similar):

"...Always use a premium-grade 5W-20 detergent oil displaying the API Certification seal...

...5W-20 oil is formulated for year-round protection of your vehicle to improve cold weather starting and fuel economy."


The graphic showing the acceptable temperature range shows a double-ended arrow for 5W-20 extending below -20 degrees to above 100 degrees Fahrenheit. There are NO references to any other viscosities or high temperature driving conditions where another grade of oil would be recommended.

evergreek
Boeing Rocks
join:2003-05-25
Austin, TX

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weird my honda dealership put in 10w30 mobil 1 full synthetic on my first oil chg!
puzz1ed
join:2005-02-20
Markham, ON

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puzz1ed

Member

Volvo does a similar thing too. Recommendation in the manual is for 5w30 but 10w30 synthethic.

Synthetics are suited for a wider range of operation so you're probably fine.

dfc888
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join:2003-07-22
San Bruno, CA

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5w-20 = CAFE = MPG
5w-30 = CAFE = MPG

= manufacturers recommending lighter oils.

Reg Mauler
Premium Member
join:2004-01-06
Phoenix,AZ

Reg Mauler

Premium Member

said by dfc888:

5w-20 = CAFE = MPG
5w-30 = CAFE = MPG

= manufacturers recommending lighter oils.
Which is exactly why I asked. What the book says and whats actually best for the car can be two different things. Plus they make that recommendation assuming you'll be using dino oil, synthetics maintain their viscosity much better and so I thought I could get away with using a higher grade.

dfc888
Premium Member
join:2003-07-22
San Bruno, CA

dfc888

Premium Member

said by Reg Mauler:
said by dfc888:

5w-20 = CAFE = MPG
5w-30 = CAFE = MPG

= manufacturers recommending lighter oils.
Which is exactly why I asked. What the book says and whats actually best for the car can be two different things. Plus they make that recommendation assuming you'll be using dino oil, synthetics maintain their viscosity much better and so I thought I could get away with using a higher grade.
I have a 2006 CR-V. Book and oil cap states 5W-20 only but I have too much 5w30 in my garage so I just change it with that (and I've been doing that ever since my first oil change). 22000 miles and still running like a champ. I redline often so I prefer the higher viscosity, and I do change the oil every 5000 miles.

The 02-05 CR-V labels recommended 5w30 but the engines of the 02-05 and the 06 are virtually the same. EPA MPG did go up by 1 mile to the gallon for highway.

tim_k
Buttons, Bows, Beamer, Shadow, Kasey
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join:2002-02-02
Stewartstown, PA

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When I bought my 2000 Honda Civic, it was recommended to use 5w-20, yet the sticker on it said it was filled with 5w-30. I guess even the dealer couldn't find 5w-20 at that time. Still, I looked around for 5w-20 and found that only Honda had it at the time. They wanted over $5/qt for regular oil. I read up on the difference and since my cars are run 99% of the time at highway speeds of 65-75 mph, I felt 5w-30 was fine to use. I changed my own oil and 5w-30 Mobil 1 was easy to find. I now have a Civic Hybrid that requires 0w-20. I was able to find it for awhile at Walmart, but I can't find it anymore. With the underside cover, I haven't been able to change my own oil. The one time I took it to Honda to change the oil where I didn't have oil to give them they charged me $12-13/qt for synthetic.

5w-20 = CAFE = MPG
5w-30 = CAFE = MPG


From what I read, you might get .5 better mpg using the 20 weight. I felt the better protection 30 weight offers is worth it.

Irun Man
Premium Member
join:2002-10-18
Millsboro, DE

Irun Man

Premium Member

said by tim_k:

..From what I read, you might get .5 better mpg using the 20 weight. I felt the better protection 30 weight offers is worth it.
I wonder about that... if the vehicle is getting better fuel economy with 5W-20 oil, doesn't that equate to better lubrication? Wouldn't that factor extend the life of an engine, as opposed to using a heavier viscosity oil?

evergreek
Boeing Rocks
join:2003-05-25
Austin, TX

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not neccessarily just means there is more resistance to turn.. Since the oil is thicker it takes more energy to rotate the parts
PrntRhd
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Fairfield, CA

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You should remember that plain engine bearings are lubricated by a thin film of oil which is prevents metal to metal bearing contact.
As long as the engine can achieve full oil pressure, and has adequate oil flow, the oil is doing what it needs to do. Thin oil lubricates just fine so long as oil pressure is maintained.
Suchaknight
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Houbytown

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Do you really think Honda would recommend 5W20 if 5W30 was better? They are responsible for the engine warranty on new cars, I don't think they're going to shoot themselves in the foot. Ford and Toyota are also recommending 5W20 in a lot of their vehicles.

evergreek
Boeing Rocks
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Austin, TX

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Sacrifice engine life for MPG?