5w40 engine oil rec....for hot weather, race conditions, etc.

It rarely gets mentioned here that 5w40 is an approved visosity oil for our engines, if not "preferred". Preferred is meant to be the oil the car is certified with, and produces the lowest emissions/highest fuel economy.

5w40 is the majority of what European cars mfrs. specify these days, as it flows fast, has high enough vis for sustained high speed driving on the Autobahn, Autostrada, Nurburgring, Mille Miglia, etc. Plus, it is "green" enough for the envirocons which have strong political clout.

Many Euro mfrs. actually have oil performance specs, similar to GM's for the Corvette. This is true of BMW, Merc, Audi, VW, etc. They call them LL (long life) oils and they figure prominently in the extended drain interval computer algorithms. M-B allows for up to 20K OCI's (oil hange intervals)! This is the reason that when Mercedes USA allowed customers to use lesser oils (mineral based) in the US, accelerated wear occured, and Merceds ate over $30M in damages.

A 5w40 is exclusively a synthetic or synblend as far as I have been able to determine. There will be some VI improver needed to span the range needed to meet the spec, but the quality syns use HT/HS viscosity index improvers so sheardown is not a big concern.

Here are some of the best as of this writing:
Mobil Delvac1 5w40 (a diesel/spark oil with better additives than regular M1)
Red Line 5w40
***New: Amsoil 5w40 "European Car Formula" - it has additives in the 2000-3000 series range, which is Amsoil's best additive chemistry
Mobil 1 "Euro Formula" 5w40

TYPICAL TECHNICAL PROPERTIES
AMSOIL Synthetic 5W-40 European Engine Oil AFL

Kinematic Viscosity @ 100°C, cSt (ASTM D-445)
14.5

Kinematic Viscosity @ 40°C, cSt (ASTM D-445)
83.6
Viscosity Index (ASTM D-2270)
182
Viscosity CCS, cP @ °C (ASTM D-5293)
5241 (-30)
Flash Point °C (°F) (ASTM D-92)
232 (449)
Fire Point °C (°F) (ASTM D-92)
246 (474)
Pour Point °C (°F) (ASTM D-97) -51 (-59)
Noack Volatility, % weight loss (g/100g) (ASTM D-5800)
5.5
Four Ball Wear Test (ASTM D-4172B @ 40 kg, 75°C, 1200 rpm, 1 hr), Scar, mm
0.35
Total Base Number 12.2
HTHS (cP) (ASTM D-4683) 4.2


*************************************************************
These can be year 'round lubes for our engines. They will flow readily at low temps (not at a 0w30/40 level, but close), but will maintain high film strength under hot running conditions, sustained high speed cruising, racing, and when towing a girl or boyfriend and luggage (bikini, sandals, what else do ya need?).

The TBN and HT/HS are outstanding - the shear of a 10w30 is usually in the low 3.X range.

Now of course, there will be a loss of a few HP due to pumping loss. But if you live where the climate demands it, or run your car very hard, it is something to seriously consider. Engines tend to like being run with a consistent viscosity - the engine "gets friendly" with the oil at the ring/cylinder bore interface.

This thread added to the "Oil Journals".

After switching to Redline 10W-40 to see if that would reduce the amount of oil consumption on my 'loose' motor. I do feel a marked lack of pep. My local Redline distributor does not carry the 5W-40. I would try the Delvac, but the anti-Mobil sentiments coming from under my hood say otherwise.

I'll order the RL 5W-40 and see how it fares.

Just to add to the 'Euro' OCI mindset;

My MB 'gararge queen' service indicator extends OCI to 2 years. Other MB's I've had went about 10K in "normal" driving before the indicator went on.

MB says it's a "flexible" indicator able to call for changes up to 12k mi., and it can "read" the oil's condition real time--optically I think. The MB dealers will not change the oil under the "free service" program before the reminder goes off. I remember getting a urgent letter from MB about using only "fully synthetic" oil for all oil changes or they would void the warranty. Dealers arround here generally use Mobil 1 0-40, but I've had one put in Castrol Syntec 5-50.

My BMW daily driver (wife's) has gone 7500 mi and no service indicator yet with 5-30 synthetic. I suspect that too will go about 10Kmi before calling for service.

Both cars came factory filled with synthetic.

Interesting that just about 10 years ago these manufactures were calling for a first service from 600-1200 miles and they would change both engine oil and diff oil at that time.

I find it hard to believe that these manufactures, responsible for engine warranties for 4 years and 50K mi, with a potential replacement cost of $50,000 (V-12 supercharged) would not do a LOT of thinking about, and testing the longer OCI. They seem to be saying that 10k mi or 24 months is ok for a "synthetic" OCI.

OCI's seem to be like baseball and religion, full of myth, tradition, and mystery.

Regards,
BD

BTW....even though it is started in our Owners Manual, Honda Canada does not reccomend the use of 5W40 in our cars here in Canada.

No, it is science and economics. The science I know - the economics I can make an informed guess about.

1) When we had to pay for service, it was as you said. Major oil service at 1k, then 3000 miles religiously since all driving is severe service, and syns are no different because they "get dirty". That was a lie then and now. It was that they wanted the revenue. Nothing much changed from an engineering perspective.

2) Now the maintenance is "free", and oils can suddenly go years and many thousands of miles. Uh-huh. Were they lying then, or now? I think the truth is somewhere in between. Yes, oils could have gone further then, and can now. But is Daimley looking ou for your best interest, or theirs?

But the mfrs. only have to get you past the warranty period. With a good synoil, you might be able to do that with one oil change! My experience with BMW NA has been lousy, in that they could care oless after you are out of warranty. The 318's eat head gaskets for luch, and we all know about the 4.0 liter V8's lack of cylinder inserts causing them to corrode away - BMW's answer was to extend the warranty a bit - big deal.

Not sure what your issue is with Mobil, but Delvac is a Mobil of a higher god.

Mobil 1 was accompanied by excessive consumption and coupled with a 2-3 mpg decrease per gallon!

It you say it is superior, then I won't be biased by Mobil 1. Since you recommend it, I have not ruled it out. As an act of faith, I'll try it on the next change. Any online stores you recommend picking it up from? Part of the reason (minor concern) is that I would have to lug around the large container it comes in for routine top offs. That extra mass will surely add 1/10ths to my commute time

Maybe I can convince your distributor to get some 5W-40?

Might be difficult...he tends to have an unquenchable addiction to GF crack and speed. If he is ever conscious, he is usually playing poker at an indian reservation and betting the farm in exchange for a set of slicks. The only thing he is good for is domination of amateurs in U3. Other than that, he is completely useless.

I know that guy.

Asura - your car, your findings, your choice of course. I got mine from avlube.com. I would be surprised if you obtained different results with any equivalent 5w40, but remember that Mobil 1 seems to formulate at the low end of each vis scale (40,30, etc.). this is likely a fuel economy strategy. Delvac meets tougher standards, so it will be interesting to see what your results are.

I am not questioning your veracity of course, but a 2-3 MPG decrease even with a GII oil would be surprising - in your case, it is astonishing, and leaves me puzzled. I have to believe it was an exogenous factor that caused it.

This was documented on the board some time ago. I'll dig for the thread...

RL 5w40 is actually more viscous at operating temperature than 10w40 http://www.redlineoil.com/pdf/4.pdf so if you think that the 5w40 will flow easier and produce more power you are mistaken. If you switched to 10w30 you should feel a difference but then of course you will consume more. It's a trade off.

RR, are you saying that RL 5w40 would produce better fuel economy over RL 10w30? How can a more viscous oil at 100Deg C do that?

I think RR was referring to the Delvac Mobil 5W-40. I actually suggested the RL since I have been happy with the 10W-30 (performance) and happy with the 10W-40 (decreased consumption).

I do not recall saying that - I recall comparing the same rated oils from diff. mfr's, and referring generally to the cold weather performance. In the winter, it takes a long while for oil to reach that 100degC figure.

I have not the time to review and memorize every brand's stats, but fuel economy also applies to the cold-start cycle, and a 5w will be better in that regard than a 10w. And you musta lso remember that static virgin oil stats vary from oil after1 few thousand miles, and it is likely that even though a specific 5w40 might have a thicker 100degC vis than a 10w40, that is likely not true after some time in use, when a 5w is more likely to shear down a bit. The differences are trivial in the big picturer anyway.

P.S. It would helpful to me in the future if you could cite the numbers so we have relative comparisons - if the csT of 5w40 is XX, list the cST of 10w40 too. I just looked them up, and it confirms what I speculated: the diff at 100degC is .5Cst higher for the 5w40, while at 40degC it is a full 4 cST lower in favor of the 5w40. One is insignificant, the other less so.

Hey RR, I was acutally referring to this first sentence of the post. While I'm not disagreeing with the easier flow of RL 5w40 over RL 10w30 at cold startups, I think that since the majority of any driving is done at operating temps, the higher viscosity of the 40, which is 15.1 vs 10.7 for the 10w30 will not produce more power or better fuel economy. It will most likely protect the engine better at the track.. Are you a member of Bob's Oil Board? I go by Quick_lude over there. Do you know Terry Dyson? According to him, Redline is probably the best otc synthetic oil for our cars. I would have liked to try maybe the 5w/10w40 but it's very hard to get locally so I had to settle for 10w30.
What do you think of the higher viscosity index of the 5w40 vs the 10w40? I know that a higher VI doesn't always mean that the oil is "bad" but that is a large increase just to achieve better pumping flow at very cold startups. I think that if you don't live in a climate or drive the S in cold conditions, the 10w40 would be a better choice. Your thoughts?
Redline specs - http://www.redlineoil.com/pdf/4.pdf

I am a member over there,and have read Tyson's posts - I like red Line, but I do not think it is the end all of engine oils - certainly some of the UOA's are very good, others merely good compared to other quality synths.

I think you and I are in violent agreement on these points. I agree that a 5w40 will not produce better fuel economy than a 10w30 once that 100degC plateau is reached and maintained, but it could in short hop cold driving.

RE: 5w40 vs. 10w40, I attempted to stay within the recommendations of Honda-approved viscosities. If we broaden the conversation to now decide which is the better, 10w40 or 5w40, then that is a different ball game altogether. We could end up talking straight grades too.

Viscosity index is becoming less and less a meaningful number, as advances in shear-stable VI improvers continue. I would agree that as a rule, the narrower the gap between cold temp vis (the "w') and high temp the better, as long as adequate startup oil flow is achieved. That is why I heavily qualified the original thread - 5w40 might be better for race, hot climates, or for people who want a year-round fill. But the Euro mfrs are specing 0w40 which has to use some VI improver to meet spec, syn or not - they understand the oil will shear down a bit and dial that into their engineering and OCI algorithms. The 0w must be there to appease the fuel economy forces, since their high power cars get lousy mileage. If you want power, torque, and good fuel economy, the "lowly and archaic" Chevy LS6 is one damn fine piece of work!

I think there are some advantages to picking an oil and sticking with it. The UOA's often show it takes several OCI's to see what a lube can really do, and Terry and other tribs have ascribed that to additive "cross-competition" - esp in the detergent area, where one mfr's additive package seems to be offsetting another.

In my case, my car sits in a heated and air conditioned garage - so a 10w40 might be a good choice for me, but a lousy one for xviper, who uses his car as a daily driver in some seriously cold weather up there in Canada. But Honda might squawk if I produce 10w40 receipts.

I have not decided what I am going to use, either in vis or in mfrs. Certainly LE, Delvac1, Amsoil, the new MaxLife full syn, and RL are in the running. They are all great products! I like to look at trends: RP seems not to be a LL oil, RL seems to doctor its formulation a lot (is it QC or just playing roulette in the marketplace?), M1 is not a LL and tends to formulate at the low end of vis ranges, Amsoil seems to thicken but generally looks good, and LE needs more research (although all of mine has shown exceptionally good stuff).

Point is, there are so many good choices, and nothing is cast in stone. That is why I think we both can agree that someone who posts "this is the best" anything better have credentials and some empirical data to back that up, or they are just blowing hot air.

You're not very ADHD-friendly, Glenn.

whatever that means...

Hehe.. he meant Attention Deficit disorder I believe..

Going to try RL 10w30, should have a UOA by the end of the summer before storage for the winter.

It means it's hard to stay focused while reading through your lengthy posts.

Yes, sound bites are not my specialty - I should break them up into "Acts" with some of Alex's hilarious posts as comic relief.

I felt a mighty pull from you,
you have long been sucking at my sphere,
and now--

No! I can't endure you!

You have sought me breathlessly,
longed for my voice and countenance;
your strong pleadings have my sympathy.
Now I am here! -- What pitiable terror
seizes you, you superman? Where is the outcry of your soul,
where the breast that built its inward world
and bore and fostered it and swelled with joyful tremor,
intent on rising to the level of the spirits?
Where are you, Faust, whose voice rang out,
who forced himself on me with all his might?
Are you he who at my very exhalation
shivers to his depths,
a frightened, cringing worm?

Good info, RR.

10W-40 and 5W-30 is what the Honda $tealers are putting into S2000s around here in Germany. I've tried 0W-40, 10W-60, and 5W-40 as well in the past 18 months in the car.

Aside from more oil consumption with the full synthetic 0W-40 and 10W-60 "race" oils, I've not noticed any other effects from the different oils.

///Robin