Somebody sell me on the idea of using 5wt motor oil year around. I am from the old school that 5wt is for the winter only and using it during hot weather would void your warranty. It gets over 100° here in the summer for extended periods of time and sometimes 120°. I wonder if manufactures have, in an effort to boost their fuel mileage numbers, sacraficed engine life.

I have the same concerns about gearboxs also. Manual transmissions used to never wear out. They always used 90wt.Hpoid gear oil and now they use ATF as a lubricant and bearings wear regularily.

Just wondering????????

 

Are you talking about stright weight or multi-grade 5w-30?
5w30 will be fine for you year round.

 

I know how you feel. It will not void any warranty when the manufacturer says to use 5w30, or 20. I use 10w30 in older vehicles in the summer, but late model with low miles, I use the recommended oil whether it be 5w20 or 5w30 year round.

 

I am of the same thought and in Texas, cool weather operation is really not that much of a concern. However, I am no longer concerned about running 5w-30 as I have convinced myself that it is OK to use, even in the summer.

Here is what CR said in its 1996 report on oil:

 

Yeah, using a little thicker oil in older vehicles is worthwhile. Good point cmlind.

 

Is not the film strength, which seperates the moving parts, less in 5w-30 than in 15w-40?

 

A lot depends on what you are driving.

I am not an oil expert yadda yadda, and my religion is synthetics so reader beware...

Older engines used different materials and machining processes so thicker base oils are probably still required. Modern engines use more "exotic" materials and are machined to tighter tolerances so a thin oil is required for flow and adequate for wear.

I am a bit nervous about the trend towards the XW20 weights and the 0WXX weights, due to a similar old school of thought and a little experience with them.

Any oil labeled as XXWYY is a multi viscosity oil and is designed to handle a range of temperatures. An example is a 5W30 oil. This is a 5 base oil that flows like 5 in freezing temps but doesn't thin to less than a 30 weight at operating temperature. For modern engines this weight oil is good for something below freezing to something above 100. From old specs and dimished memory, I recall engines in the 80s would use 5W30 only bewteen freezing and something like 80 degrees. So there is a definite limit either on the engine design or the oil technology of the times.

In other words, if you have a relatively modern new engine 5W30 is fine. If you have an older engine that is in excellent shape then I might go with a 15W40 or similar. If your engine is worn out you might want to go to 20W50, but avoid freezing.

One caveat/warning, which might be old news and obsolete... back in the 90s 10W40 had a reputation for "coking up", or essentially burning. This was because the large spread in viscosity range required a large amount of polymers which are not lubricants and were prone to "coking" at high temps, many engine manufacturers would void the warranty if you used 10W40. I am guessing this is no longer a problem but cannot say with any assurance. This is why a lot of oil makers are making 15W40 instead of 10W40.

As for the "extreme" viscosity oils like 0WXX and XXW20 I think they are for 2 reasons... marketing and fuel economy. The 0WXX I cannot imagine many of us actually requiring such a low viscosity oil. My experience in Portland Or, where it gets to freezing but not much below, is that the 0WXX synthetic Mobil 1 I used caused too much startup clatter. The 5W30 flowed plenty well, so there was no real purpose for the 0WXX.

As for XXW20, part of it is due to fuel economy and part is that some of the new engines are extremly tight. Ford has moved to this weight and oils meeting the Ford spec are supposed to be very good oils. But, my experience with my 2004 Lincoln is that the dealer fill 5W20, assumed Motorcraft, oil caused a fair amount of startup noise. When I refilled with 5W30 M1 the noise dropped down to just a brief clatter, maybe half a sec versus 3 secs or so.

So right or wrong, I avoid the 0WXX and the XXW20 oils for my engines.

A final word, with synthetics, it almost doesn't matter what weight oil you use, so the above discussion on temperatures etc goes out the window.

Good Luck,

Jim Henderson

 

Your engine will never know the difference.

nuff said

 

It's important to note that the sound your engine makes isn't always a good way to choose your oil.

I've used overly thick oils in vehicles when selling them to make the engine sound quieter than it normally would. i.e. 20W50 in the winter in a hyundai. That oil isn't going to lubricate properly, but it sure made the engine quiet.

Since 0W30 is a full synthetic, I would have full confidence on it lubricating as well or better than a conventional 5W30, because it's refined to tighter tolerances. In the end, any quality oil that meets the Ford spec should be just fine.

 

Remind me not to buy a truck from seventyseven250.

I generally stick with 10w30 and 10w40. But if a thinner oil has a good HTHS viscosity, I may run it. Have Redline 5w20 in the '92 Aerostar right now. Redline 5w20 has a HTHS of 3.3 cP, which is better than a lot of 10w30s.

5w30 is about the same thickness as 10w30, but the 5w30 (all else equal) will have more viscosity index improver (VII) additive. So I prefer not using the 5w30 for that reason. But if it is synthetic, then there is a lot less VII anyway, and so it would not matter so much. Still I like to run a 10wXX.

 

Now TP, what ever did you mean by the remark referring to the purchase of an obviously abused vehicle? Can't blame a guy for tryin'.

Now I know you aren't an amateur at info in regards to oil. Now why is it that the PAO basestocked oils won't have the VII's? Now, why do you think that dinos have a different issue? It all comes down to......what?

And when you get the answer right, you will win a hockey puck autographed by Benzik Nomenclcty, the famous polish hockey player that used roller skates on the ice. Not much control but dang he was fast!

 

I don't currently have any trucks for sale, but when I do, you can bet they'll run quiet.

 

I don't know that PAO basestock oils won't have VII, but since PAO has a much higher natural viscosity index, it won't need as much VII. Some of the tighter spreads may have none, but even Redline (so I have heard) has to use a little VII in their 5w40, but all their other grades have none. So dinos have more need for VII and, all else equal, a 5w30 will need more than a 10w30. Now, last I looked Valvoline Durablend had more Group I in 10w30 and more Group II or III in the 5w30. So in that case they were compensating the wider spread, so buying a tighter spread does not guarentee a better oil.

As for the hockey puck, send it to the Hockey Hall of Fame. I could not live with myself hoarding such a valuable and historic artifact.

As for the used truck, maybe if he had added the thicker oil in the first place, it would still be in good condition.

And now for a very important message:
"NEVER use 5W-30 or 5W-20 oil because it is closer to a grinding compound than a lubricant." --Louis LaPointe
Just kidding--heh heh.

 

I disagree because 5w30 has more VI than 10W30 and has slightly less lubrication abilty because of the added VI which adds no lubrication properties to the oil. They spec 5w20 or 5w30 to squeak out that last fraction of MPG for reduced oil shearing, not because it protects better. You will average better oil presuure with 10w30 too because under heat and pressure 5w30 in not the same as 10w30. It is only simular at the high temo test (in a range that is acceotable ) and it is not tested at other high temps.

 

Oil has to get hot and thin out before the engine/oil filter bypass valve closes. When it's in bypass oil is not filtered. Oil is filtered little in winter if your driving style is daily short trips.

So I try to sell you on 0w or 5w in winter, and except for 4.6, 10w or 15w for ambient highs over 90f.