Up oil weight with high mile engines?

[Jetronic]

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.

Possibly not just mitigate it, but actually lessen it. the higher viscosity the sealing oil in the ring pack is, the less blowby you get. That's just what higher viscosity does, it's harder to remove.

 

[Rygrego]

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.

Yes there have been plenty of engines that have done fine on 0W20 , but many more would probably still be running if they had not have stuck with the lesser grade. Tolerances have not changed as much as CAFE standards have and that's what drives the low viscosity push over the years. The standards don't give a darn about your engine life.

 

[Rygrego]

@SR5 : I didn't know 20W60 oil existed for cars.

Funny how Ferrari , Porsche and Lambos run such high viscosity oils to help their engines.

 

[SR5]

Separate from this entire thread, the 6L jug has my attention.

5L is still the most common, but may companies are also producing 6L jugs for the cars with bigger sumps. It's a more handy size, and more cost effective too. They often sell both 5L & 6L side by side, just grab the one that best suits your needs.

 

[SR5]

@SR5 : I didn't know 20W60 oil existed for cars.

Penrite HPR 30 (20W-60) was a popular performance oil back in the day, KV100 = 23.5 cSt and Zinc = 1530 ppm. I've used a lot of it over the years, I had an oil burning Audi that would drink oil. Then I ran it on HPR 30 and consumption stopped. I also used it a lot in air-cooled motorcycles that would quickly shear lesser oils out of grade.

Penrite have thicker, HPR 50 (40-70), no winter (W) rating on that sucker. More of a beater oil than a performance oil. In the words of Penrite "It is suitable for use in engines showing signs of excessive oil consumption and can be used to provide protection for older and worn engines that require a heavier viscosity engine oil to maintain oil pressure."

You can still get both oils at all the auto stores.

 

[kschachn]

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.

Interesting, I’ve used 15W-50 in my EA888 2.0 and noticed zero difference in acceleration nor oil temperature. The Audi 1.8 must be quite different. I did this to see how it affected oil consumption in the engine. I left it for the whole OCI so I did have some time with it in the engine.

 

[50yr Street Mech]

OK. I'm open for suggestions on oil grades. 13' CRV AWD K24 engine / original owner/ 0W20 it's whole life / 614, 877K on the ODO. I maintain it. I'm in New York. Avg temps 20-90 degrees. 3k OCI's . Daily driver.. What is the preferred grade at that mileage ?????? And yes, it starting to get a bit clackity clack when hot/ warmed up. Had valves adjusted 3X already. I'm thinking the clackity clack are worn bearings. No piston raps, or crank shutter. Idles beautiful.

 

[RDY4WAR]

Sometimes people inadvertently create the very problem they're trying to prevent. Arbitrarily increasing viscosity due to high mileage is a prime example of this. When you go up in viscosity, two things happen. Flow decreases (slightly, more strain a PD pump to move the same volume) and hydrodynamic friction increases. Speaking of the bearings in particular, both factors increase oil temperature rise through the bearing and thus increase bearing temperature, increasing bearing fatigue. (however slight it may be) As for the oil itself, higher viscosity often means a lower heat transfer coefficient so the oil is less capable of removing the extra heat. (again, however slight the difference may be)

If you want to protect an older engine, you want a better quality oil, not a higher viscosity one. You want an oil that cleans well, shears less, keeps old seals pliable, is less volatile, and is more resistant to acidic growth. Ideally, you run such an oil from day 1.

 

[f355spider]

The 2001 BMW and 2007 Toyota Tundra in my sig line both have over 380,000 miles each, and I just use the oil viscosity the manufacturer recommends.

 

[Carlostrece]

Sure, but that would be the lowest temperature the oil has in the system. How much higher is it in the parts where it matters?

Also, which oil temp (in which part of engine) should be considered the official oil temp?

 

[Samurai1225]

This why I won't use very thin oils. When I drove my new car home the very first thing I did was to drain the thin stuff out and replaced it with a 5W-30 oil . Posters such as you have taught me what I need to know about such matters and I appreciate it so much.

The mighty K24 showing its teeth again ...

 

[Carlostrece]

Funny how Ferrari , Porsche and Lambos run such high viscosity oils to help their engines.

Yes, but high performance engines have more need of thicker oil. Daily drivers not as much, if driven normally. Also, I doubt that Ferrari, Porsche, or Lamborgini cares about gas mileage.

 

[Carlostrece]

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.

That's good classic info that's still relevant. I figured out the same in the 80s.

You were in autoshop in 1969?! That was a while ago!

 

[Carlostrece]

There are two ways to view this...
- treating the symptoms
- treating the root cause

The reason folks will often "up the vis" in older engines is because they are often the victim of mileage induced problems like poor valve stem sealing and/or less-than-ideal piston ring sealing. Both these can result in some additional oil burning.

So typically owners will often step up a grade (or two) to combat the oil loss. Upping the vis is, essentially, a stop-gap measure that does not address the root cause. It doesn't fix anything; it only masks the problem which is likely to continue to degrade. As to when engines are treated to the traditional "up the vis ante" action, well, that depends on a slew of things which no singular answer can satiate.

Conversely, using a lube with a very stout cleaning additive package can address at least one, if not both, of those conditions. The rings can be liberated by oil when high-detergent lubes are used. And the valve stem seals can also be improved if they are not actually worn, but only restricted from fully sealing by varnish, etc. (NOTE: if the stem seals are truly worn, no oil can fix that). Essentially, restoring the engine to a better functioning state is a superior way to address the concern.
Lubes which I believe can achieve this would be HPL, VRP, and some Amsoil products.

I intend to use both approaches with my neighbor's oil guzzling 03 Honda CR-V. I'm going to switch her from 5w20 regular oil to 5w30 VRP. Thus coming at the problem with two oil solutions, in addition to replacing PCV and breather hose. Other additional low cost fixes may follow, if needed. Next I'll check for oil leaks, even though I see no oil on the ground.

As I'm sure you know, there's several possible solutions, each of which might help the OP or myself. I posted this because I think your post contained good info and I wanted to give the OP a few additional ideas to try.

 

[george1122]

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.

Did the owners manual say you could use 15W50? I'm surprised you didn't try 10W40 first.

 

[george1122]

...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.

Are you sure it is better to run thicker oil at 260f rather than the manufacturer's suggested weight at 210f? IOW, is it worth the increase in temperature?

 

[george1122]

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 never knew whether high mileage oil worked or was a gimmick. Maybe somewhere in between?

 

[george1122]

Sure, but that would be the lowest temperature the oil has in the system. How much higher is it in the parts where it matters?

Maybe there is a general rule of thumb.

 

[george1122]

Possibly not just mitigate it, but actually lessen it. the higher viscosity the sealing oil in the ring pack is, the less blowby you get. That's just what higher viscosity does, it's harder to remove.

This is especially important with today's vehicles using more flexible rings. Also, direct injection if applicable.

 

[Carlostrece]

I never knew whether high mileage oil worked or was a gimmick. Maybe somewhere in between?

Somewhere in between, IMO. HM oil does somewhat swell seals and gaskets, which somewhat reduces leaks, but it's not a miracle cure, IME. I personally have experienced no evidence that HM oil reduces oil burning. Others may disagree.

I think maybe in the past, HM oil had slightly higher viscosity than regular oil of same brand. Currently, I see no difference in viscosity specs, but the HM oils do still have more seal conditioner in them. Maybe HM also has more detergent. HM oil marketing claims that HM oil has more detergent.

I think HM oil helps a bit, but not as much as marketers and manufacturers would have us believe. That's why as a last resort I will still go up 1 grade thicker if needed (in addition to using a HM oil or VRP). I mean one grade thicker 2nd number.

For cold start purposes... I like to keep the 1st number (before the w) same as stock. For example: I might go from 5w20 to 5w30, or 5w30 to 5w40.

I won't go from 5wX to 10wX, and defineately not 5wX to 15wX. That's because my climate occasionally gets cold. People in consistently hot climates can increase the 1st number (a little bit - within reason) if they want to. Others may disagree.