30 -vs- 40 -vs- 50, etc.?

[Ed_Flecko]

Forgive me if this has been asked before, and I'm sure it probably has.

My owners manual specs my oil as 5W-30, and I often read of BITOG members who opt for a 40 or 50 grade at the upper end of the scale.

How do you know if you might want to consider a thicker oil, like a 40 or 50, and under what conditions might you even consider it? Or, should you always stick with what your motor is designed to run?

Ed

 

[Trav]

If alternative weights are listed as suitable then the engine was designed to run well on any of them.
AFAIK there is not one engine produced in the world today that is designed to run on just one weight of oil. Not Ford, Toyota, BMW, Honda, none of them, somewhere the xW20 engine is running and spec on a xW30 or xW40.

High temps, towing, track, high speed would be all reasonable conditions to move up.

 

[Merkava_4]

You would go thicker if you have too much oil consumption - or the engine has valvetrain noise.

 

[Ed_Flecko]

Originally Posted By: Trav
If alternative weights are listed as suitable then the engine was designed to run well on any of them.
AFAIK there is not one engine produced in the world today that is designed to run on just one weight of oil. Not Ford, Toyota, BMW, Honda, none of them, somewhere the xW20 engine is running and spec on a xW30 or xW40.

High temps, towing, track, high speed would be all reasonable conditions to move up.


Thank you Trav!

Ed

 

[geeman789]

Oil temperature, or more realistically expected worst case scenario oil temperature dictates oil viscosity requirements.

Well controlled oil temps in a moderately driven engine mean a 20 grade is often perfectly adequate...

A Mustang with the "track pack..." which may see track time or at least be expected to be driven hard specs a 50 grade...

My Subaru specs 5w30, 10w30, 10w40, straight 40, or 20w50 , depending on expected ambient temps and useage...

Funny, the next years new model specs ONLY 0w20...

???

CAFE...

 

[19jacobob93]

In my manual it says 10w30 for optimum performance and fuel evonomy, but an xxW40 or xxW50 are perfectly fine if a 30 isn't available. It will all depend on climate obviously but if you live in a warmer climate then any will be fine but you will lose economy with the thicker stuff as I learned.
Coming up to 210k on mine now and it doesn't use a drop of 10w30 so I see no need to go thicker

And I'll carry on getting 33mpg on the freeway in a 4.0!

There are many cars such as the Subaru BRZ that spec a 0/5w20 but run a 5/10w50 without any problems. If they are being tracked then I'm not sure how a 20 would hold up

 

[fdcg27]

Look at it this way.
A 0W-20 might save you 1% in fuel use over a 5W-30.
Over 100K with a 30 mpg car, you might save 33 gallons in fuel.
Not enough that you'd even notice, although more than enough to cover the incremental cost of a 0W-20 over a top-shelf conventional 5W-30, but still little more than a wash. You spend more for oil and spend a little less on gas.
Fuel savings alone are therefore not a good reason to use a thinner oil.
Most engines will run for long happy lives on a variety of grades.
You'll see the ocassional thread here in which someone will note than any given engine has much thicker grades recommended for it in other markets.
This should tell you that the engine was neither designed for nor really requires the single grade typically recommended in US owners manuals.
You want to try a thicker grade?
In Sacramento, you could probably use anything you wanted to try any time of the year with no problems.
In the more variable climates, like the one in which I live, a very thick grade would be fine in most any engine for the warmer six months of the year but would be a risky choice for the three coldest months.
Most engines aren't designed with a single oil grade in mind.
Rather, the maker determines what grades will allow the engine to reach an acceptable life without excess consumption or wear.
In the case of my newer Accord, this apparenlty ranges from the 0W-20 that is the only recommended grade in US OMs to forty grades in various other markets.
The engine doesn't change, only the oil grade recommendations do.

 

[Merkava_4]

Seems like the OP likes Trav's answer the best.

 

[HTSS_TR]

Originally Posted By: Trav
If alternative weights are listed as suitable then the engine was designed to run well on any of them.
AFAIK there is not one engine produced in the world today that is designed to run on just one weight of oil. Not Ford, Toyota, BMW, Honda, none of them, somewhere the xW20 engine is running and spec on a xW30 or xW40.

High temps, towing, track, high speed would be all reasonable conditions to move up.

The first 4 years(200-2003) Honda only specs 10W30 dino for S2000(synthetic can be used but still must be 10W30 and same OCI) anywhere in the world at all temperature and driving condition(daily drive or track). Starting 2004 Honda still specs 10W30 everywhere if the S2000 is operated at temp above 0F, below 0F they recommended 5W40.

Why thicker oil with lower temperature is a mystery to me. The only reason I can think of is back 10 years ago 5W40 only available with synthetic.

 

[Garak]

I guess it would just be because of cold cranking. You get the higher HTHS they were probably looking for while having reasonable winter cold cranking.

 

[901Memphis]

Oil temperature and oil pressure are reasons to move up.

 

[BrianC]

A 5w is less thick below 0F than a 10W. The w-30 or w-40 is the grade that is associated with normal operating temps of 100C. An engine operates at 100C regardless of the ambient temperature, provided the right thermostat is in place.

 

[aquariuscsm]

I usually use the thickest weight listed in the FSM. Lately I've been going for the mid grade,10W40.

 

[Trav]

Originally Posted By: HTSS_TR
Originally Posted By: Trav
If alternative weights are listed as suitable then the engine was designed to run well on any of them.
AFAIK there is not one engine produced in the world today that is designed to run on just one weight of oil. Not Ford, Toyota, BMW, Honda, none of them, somewhere the xW20 engine is running and spec on a xW30 or xW40.

High temps, towing, track, high speed would be all reasonable conditions to move up.

The first 4 years(200-2003) Honda only specs 10W30 dino for S2000(synthetic can be used but still must be 10W30 and same OCI) anywhere in the world at all temperature and driving condition(daily drive or track). Starting 2004 Honda still specs 10W30 everywhere if the S2000 is operated at temp above 0F, below 0F they recommended 5W40.

Why thicker oil with lower temperature is a mystery to me. The only reason I can think of is back 10 years ago 5W40 only available with synthetic.


The first S2000 was 1999 and in Germany it spec'd 0w40 or 5w40 all years. So it was not 10w30 anywhere in the world.
Quote:


Fabrikat
HONDA Modell S2000 2.0 VTEC, -GT (S2000)Motor B, Jahr 1999-

Mobil 1 New Life 0W-40

Anwendung Empfehlung Kapazität (l)
Motor (B) 1. Wahl Mobil 1 New Life 0W-40 (c) 4.8
2. Wahl Mobil Super 3000 X1 5W-40


And from Castrol..
Quote:
MARKE: Honda MODELL: S2000 (1999 - 2010) TYP: S2000 (1999 - 2010)
Motorenöle für Sie
Castrol EDGE 0W-40 A3/B4


Sorry it doesn't look like a 10w30 engine anywhere in the world 2000-2003 or otherwise.

 

[Clevy]

The only reason to go thicker than specified by the oem is if your operating conditions elevate oil temps significantly for extended periods of time.
For example my charger specifies a 20 grade. In the winter I run the specified 20 grade however my oil temps during the winter months rarely elevate beyond normal.
In the summer though I use a euro grade 0w-40 because I run higher rpm and full throttle quite often and oil temps can be North of 265f for quite some time.
Do you have a real oil temp gauge with numbers. If so monitor oil temps. If you find your driving conditions and habits really heat the oil up then you might want to go thicker.

 

[HTSS_TR]

Originally Posted By: Trav
The first S2000 was 1999 and in Germany it spec'd 0w40 or 5w40 all years. So it was not 10w30 anywhere in the world.
Quote:


Fabrikat
HONDA Modell S2000 2.0 VTEC, -GT (S2000)Motor B, Jahr 1999-

Mobil 1 New Life 0W-40

Anwendung Empfehlung Kapazität (l)
Motor (B) 1. Wahl Mobil 1 New Life 0W-40 (c) 4.8
2. Wahl Mobil Super 3000 X1 5W-40


And from Castrol..
Quote:
MARKE: Honda MODELL: S2000 (1999 - 2010) TYP: S2000 (1999 - 2010)
Motorenöle für Sie
Castrol EDGE 0W-40 A3/B4


Sorry it doesn't look like a 10w30 engine anywhere in the world 2000-2003 or otherwise.

You may be correct.

Someone from England posted on S2KI.com 8-10 years ago that the oil specs for early years S2000(AP1) was the same as in US which was dino 10W30. But many used synthetic 10W30 instead, especially the ones who tracked their cars.

 

[Trav]

I notice a lot of recommendations for GB are the same as USA which makes sense given their climate and slow driving regulations.