Contour Enthusiasts Group Archives Forums Modifications General Mods Why would you use 0W30?

In the summer time, why would you use 0W30? I've never seen people here say that they use 5W20, but 5W20 is a thinner oil at operating temperature. 0W30 has the same viscosity as 5W30 or 10W30 at operating temperature, while 5W20 is thinner than all those. All Ford fuel injected vehicles changed to 5W20 from '01, even in the new 3L Duratec equipped vehicles. Maybe we should run 5W20 if we're just after a lower viscosity?

a 5W20 and 5W30 will be the same viscocity at or below freezing.
0W30 is made for those extreme climates where the temps stay below 0F for extended periods of time. I really see no need for it in the continental US if you are running a 5W30 synthetic already. (Maybe Minnesota, North Dakota, etc)

The reason the new cars are going to 5W20 is GAS MILEAGE RATINGS. So the manufacturers can get away with making more SUV's. (High profit margin selling them to sheep) Yes there is likely an engine longevity penalty, but like manufacturers would care after the initial warranty ends. This penalty would be greatly increased on a high strung, high power, hard working/driven engine. Unlike the typical "commuter" driving most folks do.

BTW - Ford's 5W20 is a Semi-synthetic.
Matter of fact I believe all oils wanting to be SL rated will have to make this jump (educated guess at this point)
Guess there is something to a synthetic being better. :rolleyes: (to you folks - you know who)

Plus, I have seen a lot of new cars that use 0W-20/30. It has to do with making the oil channels smaller, and "freeing up more power from the parasitic oil pump" or something like that.

0W-30 has essentially the same viscosity at 212 deg F as does 5W-30 (9.7 cST v. 9.9 cST) according to Mobil 1 literature.
Does this mean it could be used in summer just as good as 5-30? Probably.
Most engine wear is purported to be caused at start-up, so thinner is better.
I checked my engine oil temperature several times in the past using an accurate digital temp gauge and found it to be in the 180-190 deg range, so it seems reasonable to use 0W-30 even in Florida.

Also, mineral based oils can apparently meet SL specs. I saw a can of regular Exxon 5W-30 Superflo at Kmart that said it met SL requirements.

I actually made the switch from 5W30 to 0W30 during the summer. Both oils cost the same for me and since they both have the same viscosity at operating temp, why not go with the one that will flow better at startup? Seems like a no-brainer, even if it's not as much of an issue during the summer. Now that it's winter, I'm sure the 0W30 stuff is causing less wear at startup... I mean it's almost like water even on a 20-degree morning.

I'm Using 0W30 Mobil 1 and it is fine. I change every 3000 even thpough you can push the synthetic longer. Np problems.

Living here in SE MI I always run the 0w30 for the winter monthes. Sometimes the wind chill factors can dip to -20 below and I want the most protection available

i use it cuz thats what amsoil racing series oil comes in

My brother and dad who farm run 0W30 in all their diesels in the winter as well as their vehicles - certainly makes for a much easier startup in the cold winter months! Even in my car the change from 5W30 to 0W30 is noticeable when it gets really cold, with 0W30 being the better choice for faster cranking. The car will start easily at -40C in a pinch with no plug-in