Up oil weight with high mile engines?

In going thicker there is cost involved so something like a 5w-50 is more expensive and less available. These 5w-40 Euro oils are on the shelf at Walmart and across the aisle is the HDEO versions. 5w-50 is much harder and more expensive to come by.

After the GM news I decided these 5w-40 Euros will be the one I go to. Im not worried about compatibility because Ive used them in the past without issue.
 
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That's my point, why wait for that if there's a good chance a higher grade slows down the decline. It's playing the odds.
I agree with you. I was just answering the OP's question of when to step it up a grade, with the standard Australian answer. The lore that was passed down to me.

Your logic makes sense, you don't have to ask me twice to go thicker sooner. I particularly like thicker oils that also have low volatility (low Noack), as I think these gum the rings less.

There is a lot to be said for an old school 15W40, which we still get over here as semi-synthetic PCMOs with API SP and Euro A3/B4 rated. Cheap as chips, and fine for winter in Australia.

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That Valvoline Engine Armour 15W40 PCMO probably has a better Noack ( ~10% or less) that most of the GF-6 5W30 full synthetics (Group-III) on the market today.
 
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In Auto Shop class back in 1969, the instructor told us that 30 weight oil was for engines in good condition. Spec bearing clearance back then was about .003 inch. A worn engine with .004 clearance needed 40 weight. If your Chevy was blowing blue smoke, you probably had loose rods at .005, and 50 weight was your last gasp. He was a good teacher, and there's some truth to his tale, even today. Just look at GM.
 
And on the other hand, besides a small increase in fuel consumption there's no real downside to using a higher grade. It always helps to reduce wear and it provides a cushion to help mitigate fuel dilution.
I think it depends and I've posted this observation before. I had an Audi A4 1.8T Quattro from new in 1997 until 2005. It called for 10w-30. I used Mobl1 10w-30 after the warranty expired. For some reason I bumped that up to 15w-50 around June 2004 at about 135K miles. Big mistake - huge!

This car had an oil temperature guage; the oil temperature shot up 30-50 F on this thicker oil. Acceleration was sluggish as well. After a two day weekend running five hours per day I dumped that oil and went back to 10w-30.

My take away here is that you might consider bumping it up one grade but not two.
 
I think it depends and I've posted this observation before. I had an Audi A4 1.8T Quattro from new in 1997 until 2005. It called for 10w-30. I used Mobl1 10w-30 after the warranty expired. For some reason I bumped that up to 15w-50 around June 2004 at about 135K miles. Big mistake - huge!

This car had an oil temperature guage; the oil temperature shot up 30-50 F on this thicker oil. Acceleration was sluggish as well. After a two day weekend running five hours per day I dumped that oil and went back to 10w-30.

My take away here is that you might consider bumping it up one grade but not two.

You are absolutely right. Unfortunately most people think thicker oil simply means more protection, but that is not really true. It is true that if you go one grade thicker it won`t really harm the engine in a major way, and al things considered, more likely to be more protective than not. But there are some real downsides, especially you go up higher and higher. Increased oil temperature and pressure are the first things that come to mind.

The natural consequence is the Oil bypass in the filter. As the oil gets thicker, it ends up bypassing the filter more and more often, and when that happens now you have all those wear causing particles recirculating the engine in high pressure, leading to even more wear. Also thicker oil can lead to hydrodynamic film breakdown, which will also increase the wear. Also on high RPMS, you might find the oil flowing slower, and lead to camshaft or lifter problems.

These are not really too hard to imagine, but somehow many people keep echoing eachother that thin oil is simply because of CAFE requirements (which there is good amount of truth in) and therefore we all should go as thick as possible to protect to engine.

This being said, as of this week I am also running oil that is 2 grade thicker than what my manual suggests. But that is because I am tracking the car and operate around 260f for 20 min sessions. At that temperature that oil thins to a viscosity that is comperable to manufacturer`s suggested weight at regular operating temperature of 210f. So as our friend says, apllication dictates the chemistry.
 
MY ODO says otherwise....,,,but...,,,I'm in NY.... One or two heat waves a year in July, 3 days long., then they break....... If I was in say Florida, or anywhere down south, where it's constantly in the mid 90's a good portion of the year, I too would go with a heavier oil. That's a no brainer. But, I would still stick to my 3k OCI's. I will say this much, my summer OCI's are MUCH darker/ blacker than my winter OCI's. So, climate plays a role in this big time....Again, I blame the auto makers. If you're gonna sell a car in the south, change the viscosity's on the cap and in the manual. Then the bean counters come thru the door and say " OH NO WE WILL NOT DO SUCH A THING AS THAT !!! "
 
Or 40 like GM did with the 6.2 engines a couple of months ago. I personally have never continued with a 0W20 past the first oil change on any of my vehicles. My 2017 Hondas run 5W30 , my Jeep runs 15W40 and my 16 Yukon runs 15W40. no issues at all. The 0W20 and lower are nothing but a CAFE standard and do not contribute to engine longevity.
There are plenty of engines that will and have performed just fine for many hundreds of thousands of miles on Xw20. Oil quality is much more important than running an oil weight heavier than recommended; i.e., your engine will almost certainly run longer on a high-quality Xw20 than a random minimum-quality Xw30+ of any flavor.

And as a closer, no level of oil quality or viscosity will overcome engineering or metallurgical shortcomings for a lifetime of the vehicle.
 
There are various weights of oil, of course. Is there an amount of miles on a vehicle where it is a good idea to jump up a weight in oil?

In other words, is there a certain amount of miles where to get the same function from the weight a person was using, that person needs to go up in weight?

Hypothetical example: The manual says 5W20 or 5W30 should be used. After 150K miles, does a person need to jump up to 5W40 to get the same effect that the previous oil provided when the car was newer?
Using a 5w-30 oil in a 23 year old pushrod v-6 powered Dodge truck. Spec’d 10w-30 wjen new
 
My issue is, on a new car you don't know what the actual bearing clearance is, and the load on the bearings varies constantly. Maybe you know the operating oil temperature, maybe not. and the operating temperature can go up plenty if you go over a mountain range, just because cooling is less up there.
There must be a way to check oil temp. I think with motorcycles there are oil temp gauges on aftermarket dip sticks.
 
In Australia they don't sell many "high mileage" oils, it's just not a thing here.
Rather most people step it up a viscosity grade as the car ages.

Stuff like Castrol Magnatec 10W40 or Valvoline DuraBlend 10W40, both semi-synthetic and both are API SP and Euro A3/B4 rated. Very affordable oils here. If you prefer a full synthetic we also have Magnatec 5W40 or SynPower 5W40 or Penrite 5W40 or Shell 5W40 etc.

The general rule of thumb is to step it up a grade when you start noticing oil consumption.
What's a typical range of miles on a common vehicle there where people start noticing oil consumption?
 
I think in the US you are always good to go up a grade, to just match what the same engine uses in the ROW. It might cause you to use 1% more fuel, but if it saves a cam from scoring or prevents a timing chain problem, then its certainly worth it.
What is ROW?
 
Using a 5w-30 oil in a 23 year old pushrod v-6 powered Dodge truck. Spec’d 10w-30 wjen new
5w30 and
What's a typical range of miles on a common vehicle there where people start noticing oil consumption?
Very engine dependent. If it is a subaru engine, probably around 10 miles. If BMW, they start burning oil when the technician is putting the engine together
 
There are various weights of oil, of course. Is there an amount of miles on a vehicle where it is a good idea to jump up a weight in oil?

In other words, is there a certain amount of miles where to get the same function from the weight a person was using, that person needs to go up in weight?

Hypothetical example: The manual says 5W20 or 5W30 should be used. After 150K miles, does a person need to jump up to 5W40 to get the same effect that the previous oil provided when the car was newer?
Going up one grade thicker was the old school solution we did back-in-the-day for high miles engines that leaked and/or consumed/burned oil. One grade thicker oil did reduce oil loss, IME. However, that was before high mileage oils existed.

In modern times, I would try a high mileage oil of the normal viscosity/grade. Use the brand of your choice. If that works without leaks and without excessive oil consumption, then continue doing that with that same viscosity/grade oil.

I'm currently using Valvoline Maxlife Blend. That said, after researching performance, cost, and availability, I'm now leaning towards (in future) using Quaker State High Mileage Full Syn or NAPA High Mileage Full Syn because those have cheap regular prices, often go on sale, are easily available, and in my (ongoing) research they appear to be above average performers among the low cost high mileage oils.

Give the high mileage oil time to work its magic. Like 1 or 2 oil change intervals or 5-10K miles. Then if your engine still has a leak or uses/burns oil, go up to next thicker grade of high mileage oil.

If you go up to one thicker grade, I suggest only going up 1 grade for the 2nd number while keeping the 1st number the same. For example, I'm going to increase my neighbors oil burning Honda CR-V from 5w20 high mileage oil to 5w30 high mileage oil.
 
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