[QUOTE=SpitfireS,Apr 28 2009, 01:15 PM] You won't need to change a full syn 10W-30 in 3k miles.
In any car

 

Your car will be fine for an oil change - but I'd switch back and stick with what the manual states unless Ford publishes a recomendation for another oil viscosity.

 

thanks for the input, i will change it back on the next change. thanks slipstream for explaining that, very informative

 

Hmmm....

Slipstream: you have a point about cars not being the same eventhough they have the same name.

I have seen some posts on BITOG about Ford engines having to use the xxW-20 oil because of some oil driven cam timing change device.
I don't know what Ford engines but I do recall not reading about the Focus.

What destinct mechnical differences would justify the use (and ONLY the use) of xxW-20 oils?
To be honest I can't think of any, other that what I mentioned above.
Remember: even xxW-20 oils are thick at a cold start.
Much and much thicker than a xxW-30 at operating temp.
And those engines don't have to be pre-warmed to start.. do they?

8cSt or 10 Cst... I can't see that damaging an engine.
Can you?
Using a 17 cSt in stead of a 10 cSt in an engine that revs to 9000/8000 is something different.
Btw, the design specifications you mention are most likely fuel consumption and nothing else.
CAFE remember

And a 0W-30 is just thinner than a 5W/10W-30 at a cold start.
If I could (start-up temp wise) I would use a single grade SAE 30 in my S2000.
But I can't (frost overnight last night) so I want an oil as thin as possible when I start my engine and it has to be a true syn 30 weight => 0W-30 (not being German Castrol)

What mechanical differences are there between the S2000's?
200cc extra?
JDM's have a bit higher compression and 2 knock sensors.
That's about it as fas as I know.

 

http://www.bobistheoilguy.com/forums/ubbth...1415399&fpart=1

There it is.

 

I couldn't begin to catalog the differences in specific engine, drivetrain, emission control, computer management systems... etc from one continent to another.
There are differences in model specifics here in the U.S. depending on what market the car goes to. California has requirements that other states don't have that can effect design considerations to include limiting the amount of lead in engine parts (bearings etc.) - other markets require a manufacturer to produce a certain number of "flex" fuel vehicles - which effects a number of design points.
Europe (and certain countries inside the union) have their own requirements that manufacturers have to cater to. JDM cars have ultra strict inspection criteria that usually result in cars being parted out after a given operating life (that end up in hungry oversees parts markets) after less than 40k miles.
You could go on all for a week describing the subtle and not so subtle differences in car model variations.

Oil manufacturing has an equal level of variation depending on the market/region.
A 0W30 in Europe apparently not the same as a 0W30 in the U.S.

You mentioned German manufactured Castrol Syntec 0W30 sold in the U.S., which is a full synthetic Group IV. When you look at its specs - it looks more like a "10W35" (if one existed) than a 0W30 - based on its cSt numbers.
It's "thicker" than the U.S. manufactured GIII HC 5W30 Syntec that it sits next to on the shelf - in what looks like an identical bottle, and frankly "thicker" than the U.S. Castrol Syntec 10W30 as well. Go figure.
http://www.castrol.com/liveassets/bp_inter..._syntec_usa.pdf

From their own website.

I've looked at a number of 5W and 0W20 oils available and none of them seemed to be notably thicker when cold than any 30 weight oils... and the issue here really isn't the cold weight either - but the operating weight when you're comparing oils in the OP's discussion.

You are correct - a lot of the design criteria behind the use of a 20 weight oil is for conserving energy - and to use such an oil, the manufacturer has to include design considerations for the operation of that vehicle in the broad temperature range for that market and region and that the vehicle will operate optimally, given those variables.
Using a "thinner" oil will not alone improve your mileage, especially not if you're grinding your bearings away or burning the oil at an increased rate - that wouldn't improve anything associated with emissions standards or fuel economy. One of the more important things associated with the requirements tied to the use of 5W20 oils is "sustained" mileage improvement... as in your mileage in model does not decay with normal use over time.
As you know - there's a LOT of engineering that goes into those considerations.

Cheers.

 

slipstream444 Posted on Apr 30 2009, 06:43 AM
Please don't
Just give me the ones that require a 20 weight and ONLY a 20 weight to operate properly.
Don't forget: "a 20 weight" is a range.
Anything between 5.6 and 9.3 cSt.

Lets go back to your first reply in this:
slipstream444 Posted: Apr 28 2009, 06:14 PM
Marginal lubrication?
That means that every engine is in serious trouble for the first 20 minutes after a cold start, when the oil is not up to operating temp.
For the first 20 seconds I would agree, using a 15W-xx in stead of a 5W or 0W..
Lower gas milage: yes, but not much.
The oil passages have to deal with this thicker-oil-when-cold too, no matter what oil you use.
Any fuel saving will be flying out the window when you have to keep the engine running all the time, even overnight, to keep it up to temp.


I've seen no valid arguments in this post or the post on BITOG that proves or suggests in any way that this Ford engine (with ot without the VCT system) will be damaged, even in the long run, by using a 30 weight.
Even your wallet will have less damage because it has less money in it because you will have to get slighty more fuel for that car.
That's about it.

 

You seem to want to concentrate on the cold start viscosity instead of its operating viscosity - I would argue the latter is just as important.
Additionally, there are more factors in an oil than just it's 40C or 100C cSt numbers that determine its overall viscosity range as well. Some of those factors come into play when determining the viscosity range for use.

A 0W/5W20 oil is specified for a number of Ford, Honda, Toyota (and a few other manufacturers) cars - that are designed to run THAT viscosity oil. Could you run a 10W30 in all those cars without damage etc.? I'm sure you could - but the question that should be asked is "should you?"... and the answer is arguably NO.

Auto manufacturers marketing cars in the U.S. have to produce a number of cars that meet a specific emission and fuel economy criteria, and one of the ways the manufacturer was able to meet those requirements was by designing cars that use a lower viscosity oil to greatly reduce windage and flow drag associated with higher viscosity oils. I've always considered oil to be a "part", not unlike any other mechanical part in an engine.
Just because another part will fit in place of the originally intended (and critical) part does not necessarily mean you should do it. If you operate your car the way it was intended to be operated from the factory (to include WHERE it was originally marketed and sold) - with no major modifications (I don't consider intake and exhaust systems to be major mods) - then there is absolutely NO benefit to using a higher viscosity oil.
The same is true with the S2000 and all the folks wanting to use a 5W/10W40 - it's not necessary unless you live in an excessively hot environment (as I mentioned before) or run your car on the track at high temps.
I was stationed in the Middle East for nearly 3 years and can tell you a 5W/10W40 was needed in the summertime in place of a 5W30 - in cars you would see specified for a 5W30 in the U.S.. The dealerships and part stores didn't stock anything thinner than a 5W40 with the exception of the Honda and Ford dealerships that offered 5W30 for the same models we have been talking about, that are specified to run 5W20 in the U.S.. None of those cars were built for the U.S. market, had different engines designed for the market they were built for, and none were built in the U.S. (the Hondas were built in Turkey).
And that brings me back to my original argument - do you live in an extremely hot environment (115+ daytime temps)? Then a 5W30 is possibly called for in place of a 5W20. And yes... Arizona, New Mexico, and parts of Texas would fall into that argument during the summer months. Other than that - stick to what the manufacturer specifies.

 

Hey Slip can you provide any evidence that the engines are "designed" for the lower viscosity oils?

 

What do you mean by evidence? Do you mean I'm going to buy a car, tear it apart and then compare it to a European variant? No, I'm not.

Here's what I'm going to do for you though - I have an engineering background and can tell you there's a hell of a lot that goes into designing something like a car - and of course the engine in the car. Modern cars are built to exacting tolerances - and as such, I can absolutely assure you that when a manufacturer specifies an engine oil, there is a lot of engineering that went into that decision.
Oil viscosity is not an afterthought, it's an integral design element that takes into consideration a multitude of design criteria to include what market the car is designed to operate in - environmental considerations from regulations to the actual environment it has to exist in (dusty, hot and dry - humid and cold... etc.), the components specific to that model that would be effected by the use of the oil or will affect the oil in some way, specific component performance - such as bearings, oil pump, oil transportation system - passage size, things such as oil sprayers (as used in the S2000), and the multitude of things from metallurgy to oil pressure... too many things to enumerate.

As you can see, there is a lot that goes into it. The bottom line is to use what the manufacturer recommends.
Go outside of that recommendation at your own risk - and if you do and things go south, don't try to soak the manufacturer (and the rest of us) because of YOUR bad decision - just suck it up and take responsibility for your actions. The rest of us are sick of bailing out idiots - thank you very much.