• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Engine oil

+1

Honda’s engineers specified either a 5w-30 or a 10w-30 oil for NSXs. When they designed the NSX’s engine, they sized the oil pump and the oil passages to flow a certain volume of oil at a certain pressure to the bearings, camshafts, etc. given a certain viscosity (thickness) of oil. If the oil is thicker than Honda’s engineers planned, you’ll develop good oil pressure but you’ll get less flow than was calculated. If the oil is thinner than planned, you’ll get a good volume of oil but you won’t develop the pressure at the bearings that was desired.

At normal operating temperature (100° C), a 5w-30 oil, a 10w-30, a 0w-30, and even a straight 30 weight oil all have a viscosity between 9.3 and 12.5 cSt. At normal operating temperature, all of those oils will protect your engine just as Honda intended - none of them are too thin.

At lower temperatures, all of those oils get thicker than 9.3 to 12.5 cSt. They’ll all give you good oil pressure but until the engine warms up, none of them will get you the volume of flow that Honda wanted. The straight 30 weight oil will thicken up the most and the 0w-30 oil will thicken up the least. At startup, the 0w-30 oil is the least bad for your engine.

At the other end of the spectrum, when the oil temperature goes above 100° C, as it does on the racetrack or the Autobahn, all of those oils will get thinner than 9.3 to 12.5 cSt. If you really push the engine you don’t want the oil to get too thin. A 10w-30 oil will tend to thin out less than a 5w-30 oil, which will tend to thin out less than a 0w-30 oil (especially over time). So a 10w-30 oil will tend to give you a bigger safety cushion than a 5w-30 when you’re really pushing it.

If the ambient temperatures aren’t too low at engine startup, Honda recommends sacrificing cold flow properties for a larger high-temperature safety cushion. However, if you don’t drive your car very hard, you probably don’t need that safety cushion. In that case, a 5w-30 oil will result in less overall wear than a 10w-30 because of the better startup protection (as long as you change your oil frequently).

I have an engine oil temperature gauge in my NSX. On the Autobahn, the temperature sometimes gets close to 150° C before I slow down. At those temperatures, oils thin out a lot so I need a relatively thick oil to give me good oil pressure. I’ve found that a Mobil 1 5w-50 works well but the drawback is that at normal operating temperature (100° C) it’s thicker than Honda’s engineers wanted. As a result, it gives me very good oil pressure at 100° C but if I had a stock oil pump, it wouldn’t give me as much flow to the bearings as Honda’s engineers wanted.

In summary, if you’re not going to drive the car very hard, I wouldn’t worry about putting a 5w-30 oil in it regardless what the ambient temperatures are. If you drive the car hard, a 10w-30 or perhaps an even thicker oil may be better, as stuntman mentioned. If you follow the recommendations in the Owner’s Manual and change your oil frequently, you’ll be fine. But if you think through how you use your car and what viscosity ratings mean, you may be able to find an even better oil for your car than the blanket recommendations given in the Owner’s Manual.
Oil dosnt thicken as the temps increase, but a 40 weight will be thicker at a given temp than a 30 weight. For severe suty, turbos, and high sustained temps, thicker oil eill give more protection than thinner oil.

Also a 0W30, 5W30, 10W30, and straight 30 weight should all thin out the sameand have the same viscosity at operating and higher temps. Other than warmup, all should have similar operating and higher performance.
 
Honda’s engineers specified either a 5w-30 or a 10w-30 oil for NSXs.
That's correct - 5W30 when ambient temperatures are below 36 degrees F, and 10W30 when ambient temperatures are above -2 degrees F.

When they designed the NSX’s engine, they sized the oil pump and the oil passages to flow a certain volume of oil at a certain pressure to the bearings, camshafts, etc. given a certain viscosity (thickness) of oil. If the oil is thicker than Honda’s engineers planned, you’ll develop good oil pressure but you’ll get less flow than was calculated. If the oil is thinner than planned, you’ll get a good volume of oil but you won’t develop the pressure at the bearings that was desired.
icon14.gif


As usual, their advice is for a stock car. If you have a modified car, you'll have to decide whether your modifications require any deviation from their advice. And of course, it's your car, and you can ignore their advice if you want, even for a bone stock NSX. You can even put aircraft oil in your NSX if you want! :biggrin: (I am not recommending doing this.)
 
Oil dosnt thicken as the temps increase...

I guess my post wasn’t particularly clear. I fully agree that at normal operating temperature (100° C) 0w-30, 5w-30, 10w-30, and straight 30 weight oils all have the same viscosity – 9.3 to 12.5 cSt. In addition, all of them get thinner as the temperature goes above 100° C and all of them get thicker as the temperature goes below 100° C. Below 100° C all of the oils are too thick to protect the engine properly, by varying degrees. The 0w-30 oil is the least amount too thick and the straight 30 weight oil is the most too thick.

I believe different 30 weight oils tend to thin out differently above 100° C as well. Mobil 1 0w-30 “Advanced Fuel Economy” has an HTHS viscosity of 3.0 at 150° C while Mobil 1 5w-30 “ESP Formula” has an HTHS viscosity of 3.58 at 150° C. In addition, at high temperatures the “viscosity improvers” that allow oils to have a wide viscosity range tend to break down and because of that, over time a 5w-30 oil will tend to get thinner when hot than a 10w-30 oil will.

That's correct - 5W30 when ambient temperatures are below 36 degrees F, and 10W30 when ambient temperatures are above -2 degrees F.

And just to throw a wrench into the works, from what I’ve heard from a Japanese gentleman, in Japan Honda has changed the official recommendation to 5w-40 or 10w-30 for NSXs.

In any case, NSX owners should just use a good quality oil with a viscosity specification close to what is recommended in the Owner’s Manual, using their heads to make the final decision, and change that oil regularly.
 
In any case, NSX owners should just use a good quality oil with a viscosity specification close to what is recommended in the Owner’s Manual, using their heads to make the final decision, and change that oil regularly.

QFT. There are lots of reasons to deviate from the "recommended" oil weights, but those who choose always should know the reasons behind why they're going outside of those parameters.

These threads always seem to fire people up.
 
Just to beat a dead horse :smile: - ideally I think you should:
  1. Choose an oil whose viscosity at normal operating temperature (100° C) is what Honda recommends. That would be a 30 or 40 weight oil as per Honda’s latest Japanese recommendation.
  2. Choose an oil whose viscosity at high temperatures (150° C) is at least as thick as Honda recommended for warm driving conditions. A mineral oil-based 10w-30 oil has to have an HTHS viscosity of at least 2.9 at 150° C so make sure the oil you choose has at least that viscosity.
  3. Of the oils that have the viscosities you want at 100° C and 150° C, get the one with the lowest number before the “w”. That will give you the best startup protection when the engine is cold.
  4. Change the oil regularly. If you buy an oil with a wide viscosity range for good protection at startup and good high temperature protection, it will tend to have lots of viscosity improvers that don’t last as long as the base oil does. I change my oil every 3750 miles, half the “standard duty” change interval recommended in the Service Manual.
  5. Get a good quality oil from a good manufacturer just to be on the safe side.
Per the Owner’s Manual, you can use a mineral oil-based 10w-30 in warm climates. According to SAE specifications, such an oil has to have a viscosity between 9.3 to 12.5 cSt at 100° F and a viscosity of at least 2.9 mPa*s at 150° C. Of the oils that meet those specifications, a Mobil 1 fully synthetic 0w-30 probably offers the best protection at startup. It is easier to pump when cold, has the proper viscosity when warm, and offers just as good a protection at 150° as a mineral oil-based 10w-30. It’s as good or better than a mineral oil-based 10w-30 in every condition I can think of.

However, I’d personally sacrifice a bit of the cold startup protection for more high temperature protection and go with a fully synthetic 5w-30 or just get a fully synthetic 0w-40, as stuntman recommended. Mobil 1’s 0w-40 “ESP Formula” oil has an HTHS viscosity of 3.8 at 150° C, so that sounds even better than the 3.6 their 5w-30 “ESP Formula” offers. And the 0w-40’s viscosity of 13.2 cSt at 100° C is still very close to the 9.3 to 12.5 cSt Honda first recommended when the car came out.

Whatever oil you choose, as long as it’s a good quality oil from a good manufacturer, its viscosity is close to what was recommended in the Owner’s Manual, and you change it regularly, you’re good to go. To the OP: I’d put that fully synthetic 5w-30 oil in your car now and when the time comes for the next oil change, think through if something else might suit your car's needs even better.
 
To add another Wrench to the thread. What about turbo or SC cars that use engine oil. The heat generated by these non OEM systems could change that thinking on the OEM spec oil to a thicker one due to the added heat?

That was a half-a$$ question I know. I was thinking of going to 20w-50 due to the turbo. Is this a good idea or no?
 
The head of Mobil 1 development, a real "car guy", gave an invited talk to NSX Club members during the ALMS race at Lime Rock in 2007. In response to a member's inquiry on supercharging, he cautioned against using 50 weight oil in a stock NSX engine. He noted that the stock engine is a tight clearance engine, and that 50 weight could actually cause oil starvation and increase wear.

As always, if you had your engine built by a reputable shop, he suggested you follow their recommendations.

Another interesting point he made was against the use of pure esther racing oils in street engines. He noted that in normal temperature cycles where moisture can build up in the engine, acids can form. Those using pure esther oils on the track usually flush the engine after each race to prevent acid formation.

Oil discussions are always interesting. :cool: Some people are terrified of using non-Honda antifreeze. But, when it comes to oil, many will use oil not recommended by Honda, including some not meeting API requirements. It's curious to note that Honda only first approved use of synthetic oil in the 2007 timeframe, and only one brand met their requirements back then.

I go back to staying out of these discussions, and will continue using M1 5W-30. :biggrin:
 
To add another Wrench to the thread. What about turbo or SC cars that use engine oil. The heat generated by these non OEM systems could change that thinking on the OEM spec oil to a thicker one due to the added heat?

That was a half-a$$ question I know. I was thinking of going to 20w-50 due to the turbo. Is this a good idea or no?
Depends on stock motor or rebuilt, if rebuilt then tolerances of the bearings, oil pump modifications, oil coolers, etc...

If you have an oil cooler and keep your oil temps down and closer to low 200s, then you can get away with a lower rating than if your oil temps get close to or above 300*F.

-No simple umbrella statement answer.
 
Depends on stock motor or rebuilt, if rebuilt then tolerances of the bearings, oil pump modifications, oil coolers, etc...

If you have an oil cooler and keep your oil temps down and closer to low 200s, then you can get away with a lower rating than if your oil temps get close to or above 300*F.

-No simple umbrella statement answer.

Thanks..Stock motor with factory oil cooler. I'll stick with 10w-30
 
I am really enjoying reading the analyses that are being provided. It is good food for thought.

Now, let's really give the original poster on this thread, 1st94NSX, some help and direct him to a definitive thread on which is better - Zaino or Zymol. :biggrin:
 
Thanks..Stock motor with factory oil cooler. I'll stick with 10w-30
NA, turbo, or sc? Street or track use? What ambient temps? Whats the highest oil temps you see?

The stock oil cooler and engine will have temps increase well above "nornal operating temp" (210*F) during prolonged highspeed driving, spirited driving, or track use. In these cases the temp is above and oil viscosity is below spec. Ive seen 275*+

Analyse your intended use and better yet install an oil temp and pressure gauge and choose your oil viacosity accordingly.


0.02
 
IF someone gave me Royal Purple I would go straight to Walmart, get store credit and get Pennzoil Ultra the official oil for Ferrari of north america.

Is it really? Or is it like all those European race cars that you see with Mobil I on their sides but have Motul in their crankcase?

The cost of replacing this engine might put us in the poor house. I think I will sell the box of 5W-30 to a buddy and buy 10W-30. Thanks to all who answered this thread

Don't sell your oil. You are hardly risking toasting your engine by using the wrong weight. I have driven mine for 17 years using 5w30. And that includes 10 years of tracking it. We are really debating something akin to how many angels can dance on the head of a pin. There is an answer somewhere and probably several but we'll be darned if we can agree on just one.

Besides, you live in Quesnel. Doesn't winter last 9-10 months there? You're going to need that 'winter weight' oil. :biggrin:
 
Last edited:
Is it really? Or is it like all those race cars that you see with Mobil I on their sides but have Motul in their crankcase?

I personally use Mobil, but I am an IndyCar fan. I actually witnessed in person Penzoil Ultra being poured into Helio's car before qualifying at Mid-Ohio, they really do use it.
 
........he cautioned against using 50 weight oil in a stock NSX engine. He noted that the stock engine is a tight clearance engine, and that 50 weight could actually cause oil starvation and increase wear........

I have heard this too when I was considering using thicker oil for the GTO and truck, both of which recommends 5w30.

Modern machining tolerances are now to a 1/1000ths of an inch so that a lower weight oil is better suited.
 
Is it really? Or is it like all those European race cars that you see with Mobil I on their sides but have Motul in their crankcase?

It meets, and exceeds the new GF-5 requirements which is the first for any motor oil company, GF-5 is going to be required for any 2011 and newer vehicle to run because it reduces emissions, increases mileage and extends OCI.

<object style="height: 390px; width: 640px"><param name="movie" value="http://www.youtube.com/v/uVt7eeBKvDQ?version=3"><param name="allowFullScreen" value="true"><param name="allowScriptAccess" value="always"><embed src="http://www.youtube.com/v/uVt7eeBKvDQ?version=3" type="application/x-shockwave-flash" allowfullscreen="true" allowScriptAccess="always" width="640" height="360"></object>

I've heard that current Mobil 1 consumer grade oil is not as good since they were alleged to have skipped out on the quality of their base stock and ingredients to make an extra buck profit per quart.

Even Amsoil points out that the next best thing to them is the Pennzoil Platinum (before the Ultra came out - which is better). Look at how far down the list Mobil 1 Extended (which is better than their regular version).

sso_4ball_large.gif


Pennzoil seem to have leap frogged in terms of oil technology when Shell bought them.

http://www.pennzoil.com/documents/PENNZOILULTRAFullSyntheticMotorOil.pdf
 
... GF-5 is going to be required for any 2011 and newer vehicle to run because it reduces emissions, increases mileage and extends OCI.
Car manufacturers have to meet ever stricter fleet fuel economy targets. Oils can help with that. Some of the new high fuel economy oil specifications I've seen require a low HTHS viscosity at 150° C. I'd check out the viscosity at 150° C before filling an oil into my NSX. On the Autobahn, I don't care about maximizing fuel economy with a really thin oil, I want to protect my engine.

... Pennzoil Ultra the official oil for Ferrari of north america.
Shell oils are the "factory fill and sole service recommendation" for Ferrari in Europe. Castrol is the factory fill for BMW and Mobil is the factory fill for Porsche. If one oil brand were clearly better than the rest, I assume all high-end car manufacturers would use it.
 
Last edited:
Anybody using Brad Penn oil???

T1 Racing here in the Dallas who rebuilt my SOS 3.8 NA build, only recommends Brad Penn 10w30. He says he sees less wear on cams when Penn is used. His shop specializes in custom turbos for drag racing any kind of Honda, and now GTR's.

Any opinions on this particular oil?
 
......Shell oils are the "factory fill and sole service recommendation" for Ferrari in Europe. Castrol is the factory fill for BMW and Mobil is the factory fill for Porsche. If one oil brand were clearly better than the rest, I assume all high-end car manufacturers would use it.

So far I haven't read of any F458 engine problems while Pennzoil Ultra is in the engine.

Mobil 1 in Porsche - well that makes sense.

Did you have a chance to review and comment on the other standards that Pennzoil ultra meets or exceeds? Which standards are you looking for to determine what oil best protects?
 
I'm sure Pennzoil Ultra is a good oil. It looks like a rebadged Shell Helix Ultra. Shell Helix Ultra and Pennzoil Ultra have the exact same viscosity at 40° C, 100° C, and 150° C, the exact same flash point and the exact same pour point. If Shell is trying to give Pennzoil a leg up after buying them, it's great advertising to label Shell Helix Ultra as a Pennzoil product, not sell Shell Helix Ultra in the States, and have the Pennzoil-branded oil be the official oil of Ferrari in North America.

The factory fill for Ferrari 458s seems to be 5w-40 - a viscosity that Honda approves for NSXs in Japan now. The HTHS viscosity of Shell Helix Ultra/Pennzoil Ultra 5w-40 is 3.68 at 150° C. That's well above the minimum of 2.9 that Honda specified for NSXs in warm climates so it should protect your engine well when driven hard. On their website, Pennzoil state that the oil "already exceeds ILSAC GF-5 engine cleansing and protection requirements". It doesn't state that the 5w-40 will exceed any fuel economy requirements but with that HTHS viscosity at 150° C it will protect your engine when driven hard and that's what would matter to me.

But I doubt that a fully synthetic Shell Helix Ultra/Pennzoil Ultra 5w-40 is going to protect your engine noticeably better than the comparable Mobil, Castrol, Red Line, etc. oils. Shell sponsors Ferrari so they get to advertise that they're the only oil recommended by Ferrari. Castrol has a cooperation with BMW so that's why Castrol goes into BMWs. And I assume such an arrangement is why "Mobil 1 is the exclusive factory fill, and recommended service fill, for all Porsche engines."

Edit: Shell Helix Ultra/Pennzoil Ultra 5w-40 comes from a good manufacturer, it has a viscosity Honda recommends for NSXs, and its HTHS viscosity at 150° C exceeds the minimum requirements Honda specified. Plus there's a nice historical link: Shell sponsored McLaren Honda when the NSX was developed and when Ayrton Senna won his Formula 1 World Championships. While Shell was sponsoring Honda, Agip was sponsoring Ferrari so back then Agip oils used to get filled into Ferrari crankcases. Then Honda left Formula 1, Shell went over to Ferrari, and now Shell oils go into Ferrari crankcases. And Mobil oils now go into McLarens.
 
Last edited:
Mobil 1 Extended (which is better than their regular version).

The webpage you linked to says that Mobil 1 Extended Performance has an even more “robust” formula than regular Mobil 1 that allows you to extend your oil change intervals to 15,000 miles or more. It doesn’t say that using the Extended Performance version will result in less wear in your engine.

If you remember, viscosity improvers give oils a more stable viscosity over a wider range of temperatures but have the downside that they don’t last as long as the base oil they are added to. So if you wanted to make an Extended Performance oil, one good way would be to limit the amount of viscosity improvers you put into it. Then the oil would thicken up more at low temperatures and thin out more at high temperatures but it would last longer.

Since the specifications of oils are out in the public domain, we can see whether that guess is correct. First of all, the Extended Performance version of Mobil 1 is only available in 5w-20, 5w-30, and 10w-30 grades, not in the wider viscosity ranges of 0w-30, 0w-40, 5w-50, etc. Hmmm…

Looking at the specs of the 5w-30 Extended Performance version versus the 5w-30 ESP Formula, the Extended Performance version freezes 5° C sooner yet is thinner at 150° C. It’s worse at both ends of the temperature spectrum. The Extended Performance version fulfils the requirements of GM and Ford while the ESP Formula version of Mobil 1 fulfils the requirements of Mercedes and Porsche.

It’s too bad the marketing people write the advertising texts and not the engineers. But all is not lost. You know enough about oils to think through yourself what “more robust” means and develop your own informed opinion whether the Extended Performance version of Mobil 1 is better than the regular version. Looking at the specs, I agree with nsxtasy – if you change your oil regularly, I don’t think it is.

One question; where do I go for the oil filter?

I just go to my local Honda dealer and buy the short NSX filter they now sell but there was a discussion about the issue recently here: http://nsxprime.com/forum/showthread.php?t=153626
 
Back
Top