I've been running Syn 0W-20 for the past two years now. A rep told me 0W-20 would give me better cold starts and possibly better mileage due to the lower viscosity of the oil.

About to do another oil change and wanted to ask if anyone had any thoughts about this before I place my order again. Might switch to a 0W-30 or 5W-30.

 

Amsoil Signature series 0w30 is my favorite and when I do not have any the Motorcraft 5w20 works for me. Amsoil also has a 0w20 now as well.

 

Yea, I've been running the Amsoil 0W-20. Why do you like the 30 over the 20?

 

0w20 is new and just haven't tried it yet. Been using the 0w30 for years. Thought about trying it with my next order as I have used up my last case of 0w30 and am currently running Motorcraft 5w20 because I forgot that I used up my last case. I am good at procrastination.

 

Haha, nice. Well, I've been using the Amsoil 0W-20 for bout two years now. No complaints and guess I'll probably go with it again unless someone has something otherwise convincing to bring up

 

Not trying to hijack this thread, just have a question for you Norm. I am about to change to Amsoil 0w-20 in my truck. Just curious what intervals are you changing the oil as I live just over the border from you over here in Maine. Just basing the question on we share the same weather to some degree. I'm thinking about the one year or 15000 mi interval. What's your experience with this ??

 

Once a year whether it needs it or not. That is about 12- 15k for me as well. With the 0w30 I could go longer with testing to trend my wear metals etc. The oil is rated for up to 35K. the 0w20 is rated up to 25K. I just feel that yearly is simpler.

 

Just switched from 5W-20 XL series(7500miles) to the 0W-20(25000miles).
We will see how it runs.
I only average 6-8K miles a year.

 

the heavier oil doesn't break down as easy. Oil will break down easier when under high heat. That is why diesels run a heavier oil, 15w40. Some people on here will tell you that you are starving the bearings on these "tight tolerance" engines. diesels have WAY tighter tolerances than a gas engine and are capable of tons of miles with little maintenance, but they also make a LOT of heat and the thinner oils would break down too fast

 

With all respect to you my friend, that's not correct. The oils we use today rely more on film strength and not the viscosity. Breakdown is almost unheard of anymore. Todays oils wearing the Ford spec on the bottle are subjected to double length testing at 302F which is far hotter than your engine will see and survive. Diesels use the heavier viscosity oils because of fuel dilution and that they generally are run around 25,000 miles or more between changes. But you will start seeing more and more diesels which will spec the 5w-30 oils as the diesels today are a far cleaner burning engine. Tolerance has never played a part in the oil specs in engine designs.

By the way, I did yer Gotts intake. Works really good too. I have zero difference in normal driving with it but the high end throttle response did improve. Thanks.

You will start seeing more of the 0w-20 oils. Toyota has changed their specs to a 0w-20 oil. It's only a matter of time and I expect Ford will change to it or you might start seeing some of the 0w-10 oils. With the stronger film strengths of the base oils and some of the newer anti-friction additives we are seeing tested, the 0w-10 oils are a reality. It also allows the designers to use the oil for more than just lubricating. As you probably are aware, the oil is also a coolant. The thinner oils bring more cooling capacity AT the parts and allows engine designs that were not possible a few years ago.

 

Labnerd I always enjoy reading your posts, very informative. There was talk that Ford was considering making a ceramic engine block and heads a few years ago so they could eliminate the cooling system. Sounds like the new oils might fit right in with that design. Take care.

 

then why would ford recommend a 5w50 oil for the gt500 if oil breakdown isn't a reality and why not 5w20 like the rest of the mod motors? (I'm not trying to be sarcastic)

and your welcome

 

Because the super charger makes for a lot of fuel dilution. Any engine in a racing environment like a drag engine will need a heavier oil to compensate for fuel dilution. Even a N/A engine with heavier injectors might require a heavier viscosity oil if it's driven like you stole it. Conversely though, engines like you would find in the NASCAR series often run straight 0 viscosity oils but engine life is only expected to be as long as the race- it's considered expendable and a cost of racing. But you can use a Xw-20 in a GT500 as long as you drive it like normal people would a regular sedan. OR you could use a Xw-20 oil and change every 1000 miles and hold back on the racing....like as if that was gonna happen.

DYNOTECH, Ford actually made several of the ceramic technology engines. They vary in how much of the parts are actually ceramic. I'm very familiar with the 302 engine with ceramic liners. With a normal configuration for a GT Mustang, stock HP rose to 325 +/- with just the liners. I've never heard about longevity though. I assumed yer depart. got to work with a few of these.

 

I saw a few prototype blocks with the liners when I was at EMDO but they were in early stages of assembly. Some of these I suspect were tested at Dearborn Dyno or at Roush. The talk was of a high content ceramic block and heads at one time which I never saw. I worked in the Dyno lab at Romeo Engine so we tested random in house production, Dealer and VO returns, PV testing and limited Design Validation testing of the 4.6 and the 5.4 until Canada built the 5.4. We also built the GT40 eng but our Dynes couldn't hold the hp. so that testing went to Roush.

 

It's good to see someone who knows oils. God how I hate folks that attempt to support a certain oil by saying something useless like "I use <state brand & weight> and it works great". Which is to say my engine hasn't failed yet

That being said, I'd take issue with a couple points.

Bearing tolerances ARE an issue with OEM oil specs. The only engines I know pretty well are old BMW engines. Their rod and main bearings are supposed to be at .0018" +/- a little. The OEM spec for their summer oil is xW40 to xW50. We race these things with 20W50. At red line I get ~55psi with 215-220deg oil. If I put in xW50 I get <50psi. That means that the oil pump can't keep up with the reduced flow restriction presented by the thinner oil.

In contrast, my POS '99 Dodge Ram shows much higher oil pressure at much lower rpms with thinner oil. It's engine was designed with tighter bearing tolerances and a bigger oil pump.

Re. oils today rely more on film strength then visc. Ok, sure, but there is a correlation between the two. All else being equal, high visc oils always have higher film strengths, as measured by high temp shear test. It's not complete correlation of course. High quality oils manage good shear #'s at lower visc then average oils. Redline xW40 for example, has shear #'s as good as most xW50's.

Re. racers and fuel dilution. I know of no racers that worry about fuel dilution. We change our oil after every event or two, so the oil isn't around long enough to get diluted much. Our oil analyses show no unusual build up of fuel in the oil. I can't speak for NASCAR and other high end type racing tho.