Apparently, the manufacturer has determined that 5W20 is ok for year around use. In my opinion and based on the recommedation in the owner's manual, I'd stick with the 5W20 for cooler weather and save the 5W30 for summer.

Since this is a new car, is the warranty affected by using a different oil than what is in the owner's manual?

Both of these oil weights are 5 weight with viscosity extenders. The 5W30 has more extender than the 5W20, thus the 5W20 oil has a higher percentage of oil than the 5W30.

I recall that several years ago, GM blamed 10W40 weight oil for some of their engine failures. They claimed the oil had too much extender and not enough oil. The trouble started when the mix began to break down. I don't know how much truth there is in this, but mention it for what it is worth.

http://theoildrop.server101.com/forums/ubbthreads.php
You might have better luck posting on "bob is the oil guy" forums

Very interesting article about 5W20 vs. 5W30 oil.

SAE 5W-20 Motor Oil

Should you use it in your vehicle?

The answer is simple:

You get about 1% better fuel economy, but you get 30% shorter engine life !

The above statement is based on real life experience and is comparison to SAE 5W-30 Motor Oil.

Here is a link that might be useful: Oil Article

That's not a very interesting article. It's a one sided sales pitch for Syn-Lube.

From the article

"You will definitely get better mileage with SAE 5W-20 then SAE 5W-30 oil, but not by much, usually the optimistic estimates are LESS than 1%. The bad news is about 30% reduction in engine life (from 100,000 miles or 10 years to 70,000 miles or 7 years)."

Total rubbish. with proper service intervals, todays engines last 200,000+. Proper service intervals are the good old 3mo/3000mile, adjusted slightly up or down depending on how the vehicle is normally used. Remember the phrase "Don't fix it, if it isn't broke?" 3mo/3000 is a routine that isn't broke, people should stop trying to fix it.

"That is why SynLube Lube-4-Life® is available ONLY in that grade, since we guarantee 300,000-mile service life from engines that were engineered to last no more than 100,000 to 150,000 miles. It makes that much difference!"

I can't wait to see what their guarantee really is.

Oh, they can't be serious.

"SynLube Lube-4-Life® and drive sludge and worry FREE for up to 15 years or 150,000 miles or 6,000 engine hours WITHOUT oil changes !"

The way I see it, is use their product, and as long as you drive an maintain SOMETHING ELSE.....You could travel that far in it, but not the one you put their magic oil in.

Ford and Honda both went to much tighter engine clearances. That is the reason for the different spec oil. Combine that with wanting to be sure the entire engine gets fresh lube as fast as possible on start-up and you need a lighter oil. Plus, the "5W" does not mean the oil has the viscosity of a "5" weight at 0f. It means it has the same friction that a "5" weight oil would at 0f. It's still twenty weight, and it is the oil you should use in your car. I stock eight different grades of oil for my customers. I also stock seven different automatic transmission fluids.

Use the oil that Ford says to use. No-one knows as much or more than the engineers that designed and built your car, no matter how pretty their website is.

Oh that site is a hoot!

You can buy distilled water from thenm for $10.gallon That's "Ultra Pure Water" according to the description.

But, why buy that when you can get synthetic water for $15.00 a gallon? Of course the description for that is also "Ultra Pure Water".

Oh I see,

"SynLube Ultra Pure Double Distilled Water,
a prescribed cooling system normal duty flushing fluid."

"SynLube Synthetic Water,
a prescribed cooling system dillution fluid."

The distalled water is only for flushing, you use the synthetic water with their $60.00 coolant for engine service.

Just for reference, a gallon of their engine coolant costs more than my normal charge to do a flush and fill for my customers, and that includes using the antifreeze appropriate for whatever vehicle I'm working on.

One of the reasons Ford started to use 5w20 is because of the hydraulic timing chain tensioners on their engines. They were finding that the tensioners were getting pressure too slow (hydraulic pressure from the oil pump) with the heavier oils and jumping time befor the oil pressure came up. This happened mostley in cold weather. But I think a lot off this showed up when that segment of customers that insist on using 20W50 racing oil in all of their vehicles and it ended up causing problems with these engines.

HTH
Bob

So you're saying that my Ford 500 has a timing chain rather than a timing belt, right? I was wondering about that. My Taurus had a timing chain and I never had to touch it in 235,000 miles. I was hoping this car didn't have a belt that had to be replaced at 100,000 miles, but wasn't sure. I've know too many people who screwed up engines because they didn't change those timing belts in time. To me, it's a horrible design practice to have something like that that will eventually break for sure that can wipe out a good engine.

No! I don't think I said your Ford 500 had a timing chain. I said one of the reasons that Ford started using 5W20 was because of the hydraulic timing chain tensioners. Now if your 500 has a hydraulic timing chain tensioners it might be a good reason to use 5W20. Sorry if there was any mis-understanding with my post. The thread seemed to be going in the direction of which oil was better for wear and tear. And better fuel mileage. I just wanted to point out that there were other reasons for using 5w20 besides fuel mileage and wear & tear.

As an engineer myself for a top midwest manufacturer of diesel engines, I can almost guarantee you that the 5W20 recommendation in the service manual was not put there by an engineer with knowledge of determining a single oil that would be best for the engine's life. I'm sure that the engineers have an input, however those decisions are made by marketing people and managers sitting in a meeting room and deciding the "image" or "message" they want to convey in the literature. It's part of their "overall fuel mileage average" strategy which is more important to them than trying to go from 250,000 to 300,000 miles life from an engine. I can easily see the 5W20 recommendation as a marketing "dictate" to "force" best fuel mileage for all customers. The fact that the same oil is recommended for all climates seems odd to me, and the fact is that temperature does affect the viscocity of oil. That's the reason for different grades of oil in the first place. That still exists.

The statement that "No-one knows as much or more than the engineers that designed and built your car, no matter how pretty their website is" may be a true statement, however it's naive to conclude that those engineers wrote that recommendation in the manual. They only have one vote and their vote may not even be counted in the final determination. I cannot imagine an engineer concluding that there is only one oil that is suitable for an engine in all conditions. Engineers typically look at all conditions, and they are not all the same.

And back to the timing chain. Does anyone know if the Ford 500 engine has a chain or a belt?

I use Valvoline 5W30 in all of my cars, so I agree it's a great oil. But it is NOT the oil your car calls for. Any Ford that is calling for 5W20, is calling for at the least a synthetic blend, if not a full synthetic.

Your an engineer, while it's OK to question something new, it's not OK to make random assumptions such as you did here.

"I'm sure that the engineers have an input, however those decisions are made by marketing people and managers sitting in a meeting room and deciding the "image" or "message" they want to convey in the literature"

Follow this thread from BOB's site.

http://theoildrop.server101.com/forums/showflat.php?Cat=0amp;Number=250047&an=0amp;page=37

From FCSD

http://www.fcsdchemicalsandlubricants.com/fad/product.asp?product=SAE+5W-20+Premium+Synthetic+Blend+Motor+Oil&category=Motor+Oil

So the Motorcraft 5W20 oil is a synthetic blend, yet the recommended oil change interval for this vehicle is only 5000 mi. (3000 severe service) which is relatively low by today's standards. Something doesn't seem to add up to me. Oil change interval with synthetics should be longer, not shorter. Do thinner oils break down quicker than thicker ones? What is the reason?

The problem isn't that the oil breaks down, the reason for maintaining proper oil change intervals is the oil will collect contaminents that cannot be filtered out. Even with a synthetic, 5000 miles is just about the maximum you should go between changes. Sure the oil often times "can" go further, but you only need to try and make it go too far one time, and you can suffer a failure.

All of the adds you see try and claim piston, cylinder bore, crankshaft and crankshaft bearning wear, or lack of such as the determining factor of how an oil has performed. The real measure of how well an engine has been protected is found by examinng the timing chain. Or in your engine's case the timing CHAINS, yes there is more than one. This includes the timing chain tensioners and guides. The guides are a type of nylon, and wear easily if not sufficiently lubricated. Not to mention, if the oil collects too many contaminents, the oil instead of protecting the nylon, turns around and attacks it, and causes the guides to become brittle and break.

Ever heard "If it's not broke, don't try to fix it?"

3mo/3000 oil change interval isn't broken, people should stop trying to fix it.

OK, I'm convinced to use 5W20 oil at the recommended change interval. It appears that Valvoline makes a 5W20 "conventional" oil. Am I correct in assuming that oil would be good oil for my car? When I go to the Valvoline web site for my car, that's what they recommend.

Here is a link that might be useful: Valvoline 5W20 Oil

Went to the local Wally World store. Not one single quart of 5W20 oil on the shelves there. Not conventional oil, synthetic, or anything. Not a single quart.

Interesting. What do you suppose they are putting in the customers cars that call for 5W20 that go there for an oil change?

Oh well, they do it cheap so it's OK, right??? (rh)

Don't know. Never got my oil changed there and I didn't ask them. But, it brings up an interesting thought. I wonder what oil change places or service shops do if a customer tells them he wants 5W30 in a 5W20 oil car? Do they refuse to do it? I wonder how many places even ask the customer what they want or just dump in whatever they think is best.

I can't speak for everyone, but if someone would ask me to put 5W30 in their car, when it calls for 5W20, I would turn the job away if I could not convince them to follow O.E. guidelines with reguards to a choice of oil.

BTW we stock eight differnt weights of oil. We check the manual on every car we service, and follow the charts exactly. If a car would come in and there would be a question of which oil a car could take, then we would ask the customer if they had a preference.

The Ford 500 engine is just a more slightly refined version of the Taurus 3.0 V-6, and yes it's a timing CHAIN, with hydrauliic tensioners, a gem of an engine. Really, if you get the Ford 500 Limited, it looks just like a Mercedes S-500, and will be a HECK of a lot cheaper for you in maintenance, parts, service, etc...