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**saunupe1911** · 05-13-2013, 12:54 PM

Numerous "so called" experts on numerous forums have givin their opinions on the best oil to use for our Coyote engines. Amsoil, Royal Purple, and Mobil 1 seem to dominate as far as brands, but what about weights in this Texas heat?

So what's the favorite around here? 5W-20, 0W-30, or 10W-30?

**DirtyD** · 05-13-2013, 01:41 PM

No need for a 0W in Texas.

The general consensus seems to be 5W-30, 5W-50, or 10W-30

**Luke** · 05-13-2013, 01:52 PM

Red Line is another good oil, I'll be running Royal Purple HPS 5w-30 this time around.

**saunupe1911** · 05-13-2013, 02:23 PM

Wow, no love for 5W-20. I'm probably switching to Amsoil ATM 10W-30 since it's about to get hot as hell.

**DirtyD** · 05-13-2013, 02:27 PM

5W-20 isn't a bad oil, but with the heat we face in NTX during most of the year, it wouldn't hurt to have a higher viscosity oil that won't break down under the traffic and heat combinations most of us face in DFW.

**Smurf50** · 05-13-2013, 06:10 PM

I am using 5w-20 Motorcraft synth blend

**Dan12GT** · 05-13-2013, 10:10 PM

Amsoil 10w30. Great stuff no issues. Been on it about 4k miles. I also switched to their trans fluid too. Made a good difference in shift smoothness.

re-rx7 · 05-14-2013, 01:12 AM

"More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. Its more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem. It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity then we should concentrate our attention at reducing engine wear at startup"

**DirtyD** · 05-14-2013, 01:28 AM

Originally Posted by re-rx7

"More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. Its more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem. It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity then we should concentrate our attention at reducing engine wear at startup"

Exactly why it is useless and possibly harmful to run a heavy weight (0W) oil in a warm to hot climate like Texas. We will never see low enough temperatures to utilize the cold viscosity of the oil, so stick to a 5W or 10W is really all you need. But having a heavier hot viscosity is a good thing.

re-rx7 · 05-14-2013, 01:33 AM

Most if not all wear on an engine come upon startup. At operarting temptures the oil is around 212degrees or so. At htis temp all oils pretty much have the same thickness its the startup that makes the difference. At 75 degrees the thinner oil will actually better lubricate.
Now let me discuss what people think is a similar situation to racing. That is hot summer traffic jam driving. Your car should be able to handle this. If you have problems then you have a problem with your car, most likely in need of a cooling system overhaul.

When you drive that car down the road mid-winter in upstate New York or mid-summer in Florida the engine and oil temperatures will be around 212°F. But your Florida vacation is suddenly altered by a hurricane. You have to get out of Tampa, but so do a million other people. It is now 95°F and you are in a snarl. Everyone thinks they need a thicker oil for this situation. This is false.

Your engine is not producing much heat at low RPM and low BHP output. The production of heat is relatively slow. It can easily be transmitted to your cooling system. The problem is that your cooling system has trouble getting rid of the heat. The oil and the coolant will slowly rise in temperature. They both rise together. The increase is no big deal for your oil. It goes to 220°, then 230°F. The problem is that the cooling system can only handle heat up to 230°F. After that you overheat the cooling system and the car must be shut off. The oil never got that hot, It was just that the water got a little hotter than its system design.

You now see that overheating in traffic is a cooling system problem and not an oil system problem. Do not change to a thicker oil based on your traffic situation.

**DirtyD** · 05-14-2013, 01:43 AM

You are right. I failed to realize that when talking earlier. A heavier weight oil is definitely something to have if you do some sort of racing on the weekends though.

re-rx7 · 05-14-2013, 01:51 AM

Originally Posted by DirtyD

You are right. I failed to realize that when talking earlier. A heavier weight oil is definitely something to have if you do some sort of racing on the weekends though.

To an extent I agree. I can see race oil being benficial at the track in some very hot weather with a heavier weight but there is a point where it is detrimental as increased flow will result in increased cooling by the oil. This is a good thing. You would probably want more oil flow in these situations and you get it. The hotter oil thins and this increases flow. The higher flow works harder to separate the engine parts that are under very high stress. It all works out for the better. Higher revving engines need thinner oils. You do not necessarily need to go to a thicker oil while racing. Only experimentation will tell.

Hagen3great · 05-14-2013, 10:34 AM

Pennzoil Ultra 5w-30

**BLK2012GT** · 05-14-2013, 11:09 AM

Amsoil fully synthetic 15w50

**saunupe1911** · 05-14-2013, 02:58 PM

Interesting feedback