I found 0W-20 synthetic oil in Mexico

I have written in the past about the peculiarity of the Mexican culture that makes people think they need 20W-50 oil in their late model cars.

Yesterday, we drove into Tehuacan, second biggest city in the state of Puebla. Our reason for going on a four hour round driving trip was my wife’s desire to eat a certain stuffed pepper covered with pomegranate pieces. I am not making this up, hee, hee. She bought a second order to take home.

We spent time shopping for groceries, too.

I hit the oil sections, just out of curiosity. Bodega Aurrera, a Wal-mart subsidiary, had zillions of containers of 25W-50. I did find one bottle of 10W-30 just to keep in my car in case of need. There were also some 15W-30 or 40, I forget.

Then, we went to Wal-mart. Again, lots of 20W and 25W. But, also some 10W, even some 5W. But, the Mobil-1 was 5W-50.

HOWEVER, they did have just a few bottles of Rosenfrash (spelling?) Speed racing full synthetic 0W-20. In US dollars, it was around $10 a quart.

There was a greater quantity of 0W-20 dino oil near by.

I just cringe thinking about those horribly expensive new cars, having 20W-50 oil put in their motors. I can’t even imagine what that does to those fancy valve trains!

Are late model automobiles rare there? Apparently very few cars are using the 0W oils there and if so are late model cars there showing any indication of a high rate of valve train failure?

And what are the new car dealers using when they service vehicles that are in warranty?

It is strange. Maybe it’s human nature to think that bigger numbers are better. Somehow zero-weight oil sounds bad.

They probably eventually wind up in the shop, because the variable valve timing is no longer working correctly

Or the engine has sludge

And nobody can figure out why . . .

I’ll bet you lunch that in none of the owner’s manual for recent Mexican-spec cars, does it list 20w50 as being acceptable. Probably not even for diesel vehicles

The thing I don’t understand is how does the engine know how hot it is outside? I mean an engine runs at over 200 degrees whether its 110 out or 40 degrees out. What difference would the outside temperature make once the engine is warmed up, and how could that affect the oil to be used? It would be like the outside temp being 220 degrees all the time. Now I understand the heat dissipation rate is less when warmer but that doesn’t change the operating temperature of the engine.

@Bing I though most of the wear on an engine happened during warm up. So the viscosity of the oil at start is crucial, and that’s really measured by the 0W rating, isn’t it? Once the engine is warm, like you said, it makes no difference about the outside temperature.

Every search that I have made re 0W and 5W viscosity oils being recommended by manufacturers has, in the end, noted that fuel mileage was the determining factor and the mpg improvement was in the fraction of a mpg. None indicated that significant increases in engine life was the reason for such light oils. And while the old school STP and Motor Honey products are fading into obscurity there was some truth in claims that such products would “cling” to the wear surfaces after hot shut down and offer substantial lubrication when the engine was restarted after cooling down and the oil draining out of moving components which is what heavier oils would do. So, like many situations there are 2 or more seemingly contadictory opinions and each has its merits. In El Passo Texas I would feel safe using 20W50 oil in my 4.9L Ford I6 but in a Minneapolis winter I would insist on 10W30 in it and if I owned a 2015 Toyota I would likely use exactly what the owners manual called for. Those Lexus dealerships in the UAE were using 10W40 and 20W50 oil for many years and the oil was sold under the Lexus brand. As they say, to each his own.

I would like to see some studies proving or disproving that the wrong oil . . . too thick, usually . . . will play havoc with today’s variable valve timing

I know there are countless stories and personal experiences out there, but I’d like to see a published study

The study should state at what mileage/time the damage occurred, what viscosity was used, what viscosity SHOULD have been used, etc.

In his book “What You Should Know About Cars” written by the late Tom McCahill and published in the early 1960s, McCahill didn’t like multi-viscosity oil and in fact not only did he use straight weight oil in his own cars, but ran one grade higher than what the manufacturer specified. If the manufacturer specified 20 weight, Tom used 30 weight and gave extra time for warmup. At the same time, Les Viland, who drove in the Mobilgas Economy Run and often won,_used 5 weight oil for the run. However, in his,personal cars, he said he used 10_weight. Now I know times are different and I go with the recommendation in the owner’s manual. However, once the engine is warmed up, I am not sure what difference a higher viscosity oil would make.
I once put 10 weight into a,Lauson lawnmower engine and the engine got really too hot. I immediately changed the oil back to 30 weight. On the other hand, the oil bath air cleaner specified 50 weight. I couldn’t find 50 weight and finally decided that 30 weight would work and it did. Even after 65 years, I still don’t understand why 50_weight in an oil bath air cleaner was specified.

Me, too, db. All I know is in various places when snooping on the web, it has been stated that the variable valve timing needs a certain weight oil for proper operation. So, how does one find out for sure?

I know a man who lived in UAE for 2 years. He certainly did not drive Lexus at all. But, he adapted to the heat, and used to run in the sun for two hours well over 120 degrees. When he visited us in McAllen, he went out for a two hour run in the sun. It was only 95 degrees and he was upset because he couldn’t even work up a sweat.

He said it took him 3 months to adapt to the heat. We don’t visit McA that often nor for that long, so the heat is hard on us. he said it would take me six months to adapt, at my age.

I did work with environmental chambers in my work. I think a car cooling system is designed for a certain amount of temperature difference, and if it isn’t there, heat transfer will be reduced, and he engine will run somewhat hotter. Tom McCahill used to make negative remarks about how hot American cars ran in the summer.

Also, from non-related temperature work, I do not think that heat transfer is linear with a varying temperature difference.

No, actually, I am sure the heat transfer is not linear with changing temperature. We would put thermocouples in various places in our products, and record the temperature over chamber emperature range. As the box cooled, the change in temp slowed to a crawl. What is that curve called? Either geometric or logarithmic? But, a very sharp curve.

For other comments, I have no access to major repair services nor dealers. Most mechanics are self-taught, which mostly means non-taught. The best ones studied at the factory and were taught by the manufacturer. There aren’t many of them. They don’t have tech schools like that, at least not in the degree we do in the USA. And, books of any kind are scarce and horribly expensive.

Even the city mechanics here do not have a simple code reader. The garbage pickup showed -30 degrees engine temp when warmed up. And, a failure which seems to indicate valves out of sync with crankshaft. Their solution was to get rid of the driver who complained about it and put in another man.

It is more than just the valve operation. Someone has said that the new engines are made to very tight tolerances and there are places in the motor where heavy oil will simply not be an adequate lubrication.

Yeah, we need a rich guy to buy a bunch of Lexus and run them around with 25W-50. Hee, hee.

Note: strictly coincidence that two of us referred to McCahill at the same time with crossed posting.

http://www.popularmechanics.com/cars/how-to/a53/1266801/ Does not directly answer our questions, but still interesting

http://www.cars.com/go/advice/Story.jsp?section=maintenance&story=choosing-oil&subject=oil specifically says using 20w-50 in a car designed for other oil may void the warranty.

Keep in mind that the oil doesn’t get the same cooling as the water in the engine. The bulk oil temp in a car running in 70 degree ambient isn’t the same as the bulk oil temp as an engine running in 100 degree ambient and Mexico can be really hot!

A previous car of mine had an oil temp gauge that showed the oil temp barely getting to 180 degrees in the cooler months with the engine running at 195. In the hotter, summer temps of 85 or so water was 205 and oil was 220, a 40 degree gain. Running at the track or up and down hills, oil temps would rise to 250-260 degrees and water would stay at 205. This car had no external oil cooler.

A recent article about the new Camaro had the magazine testers seeing 305-310 degree oil temps at a track day. The Chevy engineers told them to switch the 5w30 for 15w50 oil because of the very high oil temps they were seeing. This engine was the new one with cam phasers. They also told them they typically suspend testing if oil temps reach 310 degrees.

Maybe the high temps the Mexicans see in the desert areas have taught them to reach for the thicker oils.

From 1973 until about 25 years ago when I developed a heel spur, I would run at noon when if was over 90 degrees and had no problem. I would also run outdoors in the winter as long as the temperature was above 10 degrees and the sidewalks weren’t slick. I drank the same stout beer year around, but I suppose I should have switched to Budlite or its equivalent for the winter months. Maybe what was needed for us runners is a,multi-viscosity beer. Now my engine is showing signs of wear and I only walk 3 miles a day–takes,ms 45 minutes. I am also not able to go as many miles on a beer.


Recent engines are built to very tight tolerances

So tight, that not so long ago, they would be considered race engine tolerances

Tight tolerances and tight clearances aren’t the same. Bearings and pistons are much looser in performance engines that I am familiar with. Of course those were dirt track stock car engines but they were quite serious competition cars.

“As the box cooled, the change in temp slowed to a crawl.”

That is Newton’s law of cooling: Newton’s law of cooling states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings. Therefore as the temp difference goes down, the rate of heat flow goes down also.

Or, the amount of heat transferred is directly proportional to the temperature difference.

Good data, Mustangman. Thanks.

I live in the Central Highlands. I don’t think I have ever seen 100 degrees, even in the hot months, April and May. In general summer conditions up here are cooler than in the Midwest. (Iowa; Nebraska; Illinois).

So, I am convinced there is no logical reason whatsoever for using 20W-50. Just a quirk of the culture which all cultures seem to have.

Or, the amount of heat transferred is directly proportional to the temperature difference.

it is nit-picking, perhaps. Or, perhaps we are saying the same thing in different words. But, no, not directly proportional to the temperature difference. It is on a curve. We did the graphs.

When we put thermocouples inside a box, the temperature changed very fast at first. The last 5 or 10 degrees took a very long time.

Maybe I need to consult with a dictionary?

For reference, my car has an oil temp gauge. In the winter with the car warmed up, the oil temp will pretty much match the water temp, around 205 degrees, though it takes a long time for the oil to reach that temp.

In the summer, if I’m beating on the car a bit with ambient temps around 95 or so, the oil temp will get up to 230, while the water temp will rarely exceed 215. On a light acceleration you can see the water temp creep up 2-4 degrees then quickly go back down. Oil takes about 5x as long to climb and fall it seems. The highest temps I’ve personally seen were about 240 for oil, 220 for coolant after several hard accelerations on a 100-degree day. I use the manufacturer-recommended 5W-20 oil, but do use full-synthetic.