I have a Taurus with the 3 liter Duratec engine. Recommended oil is 5w20. It's not always easy to get in my area. The 5w30 is everywhere. Is there any problem with using 5w30 instead if I can't easily find the other? Do any of you use it in your Duratecs?

Also our Aviator with 32v 4.6 liter V8 is supposed to burn 91 octane gas. Does anyone here have one that they have tried 89 or even 87 in? Any problems with lower octane? How low can you go?
It's my first post here, thanks!

Welcome to the forum oldfarmer!!!

First on the oil question, I have a Honda CR-V that specs the same 5w20 oil that Ford is requiring these days. In my opinion from what I've read, it is strictly for CAFE requirements for that extra 2 to 3% mileage increase that a 5w20 can offer, but not necessarily with every vehicle. I've used 5w30 ever since removing the factory fill for the first oil change, and am currently running a 0w30 in it for the onset of winter. If it gets particularly cold, I might even try a 0w20, but that would be for a limited time and ONLY if it gets cold for an extended period, like weeks below zero. I also prefer synthetic based lubes, but I just want the extra protection/longevity that they offer. Brand preference is up to you.

Second question on the gas, stick with the 91 or better. The first and foremost thing you will notice is a loss in mileage with lower octane. This engine is a higher compression engine that requires fuel to burn a little slower (the higher the octane, the slower the combustion rate), and in using lower octane, it will start to knock and ping more than is acceptable in a modern engine these days. I speak from experience, as I've tried this myself, and was not happy with the results. I ended up spending more in fuel costs due to the increased consumption, and the car ran like crap. I don't have a favorite gasoline brand, I just look for the least expensive that I know gets a regular fresh fuel delivery.

Hope this helps ya out a little!

OK. Thanks for assist.

old farmer ,

API SM 5w-30's , the better one's anyway are very very close to having the same cold weather pumpability and pour point as the previous SL 5w-20's had .

Most of the SM 5w-30's are very good oils . Some are even better I have no problem using certain 5w-30wts in my own Duratech V-6 .

The 5W30 will be fine, but I would use the 5W20 if it is available. You will not ever detect any more wear, and you will get a little better mileage.

In UK Honda CR V is a 0W40 recommendation.
If Honda's data shows 5W20 is best then they would specify this or at least 0W30 in UK. Engine requires this oil or better wear appears a nonsense so pure CAFE!!

Viscosity really doesn't matter, it's how well the oil is formulated. If you can get teh same wear with a lower viscosity, then use a lower viscosity. It's that simple. Too many people worry about what viscosity to run. Realize that most peole throughout the last 20 years have been running 5w-20 oils and still getting long life out of their cars! Reason being is that most 5w-30's from awhile back sheared down to 5w-20's. Asia is now jumping on board and calling for 20wts as well. I put German Castrol in my Honda and it felt VERY sluggish.

I think the mistake people make is they say, oh it's CAFE, therefore it sucks. Wrong....to compensate for lower viscosity they have improved the anti wear additives. Havoline conventional oils all contain 490ppm of Moly. It's a great oil. Motorcraft said their testing of the 5w-20 outperformed their 5w-30. Go figure.

Hi Buster
!! expectatiom
Known for some time (see below) but if you take the reverse of CAFE it's additional bhp. Additional bhp is a big seller and easily linked to Motorsport even bigger seller. The logic to drop viscosity is easy.

You posted on C Edge R&D - 0W30 is used and also 10W60 also a go figure! or perhaps discuss!

The ford modular has been mentioned and in UK this can be specd from 0W30 to 15W50 no surprises if one has been tweaked.

My perception is that the US is mineral and 3K based, this is economic, but GIII is Dino classified, wheras Europe is Synth (inc GIII) based with longer OCIs. These economics dictate the perception of viscosity.

CAFE has no interest to me, only interested in oil performance.


Pro R 0W/20
Max power 134.4 BHP @ 9750 rpm
Torque 78.9 ft-lbs @ 7400 rpm

In other words, 3.7 BHP/2.9% increase from GTI to Pro S, a 2.8 BHP / 2.1%
increase from Pro S to Pro R, or 6.5 BHP / 5% overall. Not bad, just for changing
the oil, eh? More to the point, a keen bike owner would have paid at least
£1000 to see less improvement than this using the conventional approach of
exhaust / intake mods, ignition re-mapping etc.

Am I recommending 0W/20 for high performance engines? Well, perhaps not! The
Pro S 5W/40, which is a 'proper' PAO/ESTER shear-stable synthetic, will look
after a powerful engine better than a heavier viscosity 'cave at the back'
conventional oil, and provide a useful few extra BHP. (On the other hand,
the 0W/20 was very thoroughly developed to give good anti-wear protection.
I think I was on 'Blend 6' before Kawasaki was happy with it!).

Hi MG, I don't disagree, but consider that many high performance cars and longer drains must account for fuel dilution. I'm not saying thinner is better. Not at all. But for 99% of most drivers here in the US, that never go above 85mph, a 5w-20 (which btw are all group III and group II+ now) are absolutely fine. CAFE is the reason, no doubt. BUT, you can make an oil of lesser viscosity perform very well if need be and that is what has happend. Honda would not put it's reputation on the line of 20wt oils would cause engine failures. That is my opinion. Would I race with a 5w-20? Not unless it was Redline or FUCHS. To complicate matters, not only are oils getting more thin, they are reducing the amount of GF-4 as your well aware of.

Hi Buster

Fuel dilution is a start up issue - thick oil fuel - thin oil less fuel again Synth Dino/ or thin dino?

No engine failure - we are looking for optimum.

Another preconception
US drive for miles at 60mph
UK will thrash a car in all gears up to 140+mph

Spec an oil or both markets?

If you track a car say at weekend 5W20 appropriate?

Even my old designed V8 can use a 5W20 at 0F

Setting aside CAFE and preconceptions - best viscosity additives etc for circumstances is the goal.

At the moment even start up wear remains a unexplained, let alone additive pressure/temperatue effectiveness.

MG I agree. I wouldn't use a 20wt under the conditions you mention. No doubt 20wts are driven by CAFE. However, under the right conditions they perform very well.

But more and more of the engine makers are using bearing materials that are more suited to running dirty , thin oil through .

Split the difference and run 0w30. That way you have the best of both worlds: easier pumpability for startups and 30 weight protection.

Motorbike,

Does not explain the same engine but diff visc spec between US and Europe.

quote:

Originally posted by MGBV8:
Motorbike,

Does not explain the same engine but diff visc spec between US and Europe.

A guy can run dirty , thick oil through these newer type bearings as well

I thought with adoption of CAFE all wear particles have been reduced to comply, wheras in Europe they will remain the same size until further notice!

What is this censorship issue?