Engine Oil Viscosity - wasted energy during warmup

[bbhero]

Well that makes sense. I don't feel it would hurt the transmission in any way given that I wouldn't drive it super hard. A lower gear ratio within one standard lower deviation would not cause any issues given rpm is not pushed much over 3k.

I believe my step fathers Toyota Avalon actually does this in that even while in automatic operation it kept the car in lower gear to assist in getting temps up quicker. This would be acting in similar fashion just that I would be controlling the gear ratio to a degree. Also in a way it would help transmission fluid get up to the operating temp faster which would be probably a good thing too. Again, within reasonable limits

 

[Shannow]

Within reason is reasonable

Note that in the left chart, the torque is constant, RPM varied...that actually means that the power output was 3 times the lower line.

But in the RHS chart, the RPM was constant, and the torque increased 6 fold...that's 6 times more power output for little change in oil temperature rate.

So revs clearly wins over load.

If you aren't straight out the driveway onto the highway, holding a gear or two will (probably) help wear and economy.

 

[bbhero]

Well its ahh probably a 1 km to route 199 where the speed limit is roughly 100 km/ hour. In the way out to 199 the speed limit is between 50 and 75 km/hr. So, its not too bad. Not like leaving pit road in NASCAR or Australian V8 super cars series

 

[demarpaint]

Now that I'm thinking about it, I hold lower gears longer with my van when cold, and have done so as far back as I can remember. I never gave it any thought with the AT, other than driving slow and easy when cold. I make sure not to mash it getting onto the highway which is about a mile from the house. We have a long acceleration ramp, so merging with traffic is usually very easy.

 

[69GTX]

There's no "2" choice in my automatic transmission. I'd not be comfortable using "1" and getting 3,000 rpm at 20-25 mph. And the people stuck behind me wouldn't appreciate it. But "3" is normally used for speeds up to 35-40 mph. That could work fine for the first 1-2 miles, though again, with a speed limit of 40 mph just 1/2 mile from my house, would often tick some people off. I've always wondered if an automatic transmission experiences any negative issues by being continually driven with a lower speed selected that is well below the point where it normally would shift higher (ie say running at 50 mph in "3" for 20 miles).

I'd had always figured lower rpm for the first few miles for a more even warm up to reduce stresses, especially across the walls of the piston bores and the thick block dimensions. I guess my power plant training gets in the way of that where following heat soaks and methodical heat ups for combustor chambers, boilers, and reactor vessels are critical to not over-stressing them. Are there papers as well on these higher rpm car warm-ups (2500-3000 rpm) that show no additional engine issues after 100K-200K miles?

This is all helpful though as rather than using 1500 rpm for that first 1-2 miles I'm going to push that up to 2000.

 

[Joe90_guy]

One of the 'odd' things about US oils in general is their relative CCS. Take 5W30s for example. The CCS-30 limit is 6,600 cp max. However if you look at the measured CCS's in PQI, you'll see they are way lower than 6,600; on an eye-balled average they're around 4,000 cP. Some of the tested oils are closer to being 0W30's than 5W30's!
Why do this? It makes for a worse oil with a much higher VII polymer loading, that's more expensive to make and has a higher Noack. The reason of course is to get the KV40 down as low as possible to give the oil maximum chance of passing the API fuel economy tests which of course takes into account the energy sapping engine warm up phase.
Personally, I've always thought this to be completely daft but there you go...

 

[OneEyeJack]

I just take it easy for about a mile with my Honda driving between 25 and 35mph then it's down a ramp for a couple of hundred yards to the freeway and a gradual acceleration to 65/70. I figure that moving is better then idle time. I use a 0w-30 oil and it's been working just fine. In my case I'm a bit careful with the warm up because I'm dealing with a carburetor and not a computer controlled FI setup.

 

[lubricatosaurus]

Originally Posted By: Shannow
Another warmup paper...

http://www.nrel.gov/docs/fy15osti/63255.pdf

Complete with dipstick oil temperature measurement.


Great thread Shannow. Nice to get a grip on viscosity effects on fuel economy. We know there is a few percent improvement, whether or not we can "see" it or notice it.

Poking fun at the tech paper cited at the very beginning of this thread:
An exact quote:
"The problem of cold start is take place on
vehicles which are used for short journeys, in that
case the engine doesn’t reach its operating
temperature before being the vehicles stoppage."
.... Just awesome.

The Indian tech paper does have some good observations, although the reporting is atrocious. For example, they should have at least told us the type of oil used in their graphs, and at what temperature the engine was started at.

The NREL research paper is much easier to understand, better funded, and complete.

 

[Garak]

Originally Posted By: Joe90_guy
Personally, I've always thought this to be completely daft but there you go...

Maybe, but there are enough people in north central states and central Canada who do appreciate a 5w-30 that isn't bordering on a 10w-30. As for daft, Imperial Oil already has oils in Canada that the U.S. doesn't get to see, not even in Alaska, but those tend to be HDEOs.

 

[Joe90_guy]

The way I see it, the API fuel economy tests have effectively subverted SAE J-300 for the ILSAC grades. Instead of having 'sensible' 10W30's, 5W30's and 0W30's, the US now has 7.5W30's, 2.5W30's and -2.5W30's. Whilst I might agree for cold regions, a bit of cold start 'reserve' isn't a bad thing, this comes at a significant cost to warmer parts of the US.

To understand why, you need to understand the nature of Group II mineral stocks. Just as with Group I's, the natural home for Group II's is narrow cross-grades like 20W50's, 15W40's and 10W30's. As you go wider and lower, the limitations of these simple stocks become more apparent. The problems manifest themselves as high VII requirements, low aggregate base oil viscosity and high Noack volatility. I would say that making a 'tight' 5W30 all Group II oil is already pushing your luck. Making a 2.5W30 is taking things to a point that is beyond sensible.

The only way this can happen in the US is because of three 'Get Out Of Jail Free' cards that the industry has given itself. The first is obviously the 15% max Noack spec which no-one else in the world uses. The second is using fragile, high SSI VII's. The third is the horribly low pass standard of the Sequence IIIG Weighted Piston Demerits parameter. This was a measley 3.5 min (out of 10) for GF-4 and a not much better 4.0 min for GF-5. Open up the link below...

http://www.swri.org/3pubs/brochure/ae/pdf/SequenceIIIGTest.pdf

Look at the state of the pistons that are considered to be a pass in this key test. It's not good is it? And remember that is after just 100 hours of operation (about equivalent to one OCI). Stuff like viscosity increase gets reset every time you change your oil. Piston deposits on the other hand accumulate with every oil change. If they are this bad after one OCI, what are they like after five or ten?

Two of the things I've noticed in recent years are almost routine acceptance of some oil consumption and the occurrence of stuck oil control rings in the US. Coincidence? You judge...

Just my own personal opinions of course...

 

[Benito]

Originally Posted By: 69GTX
There's no "2" choice in my automatic transmission. I'd not be comfortable using "1" and getting 3,000 rpm at 20-25 mph.


This solution might work:

- Place transmission lever to "D"
- Accelerate until you feel the transmission shift into "2"
- Place transmission lever to "1"

The transmission should be smart enough not to shift to "1" but it should hold in "2"

 

[bbhero]

Benito... Some transmissions are on the how shall we say the shorter than average bus. My Ford Fusion which was a very good car... If one did what you said... It would be at 5,000 rpm. Transmission was not smart or set up that way. That having been stated.. The 6 speed transmission in that car was extremely good. The weakness in the big three was their transmissions. This why they joined forces to develope the six speed transmission. And this version was very well done. But it only had two options D and 1. In drive 1 it would turn 4000 rpm going much over 15 mph.

 

[69GTX]

My automatic transmission with fwd gear selections of 1,3,D has fully automatic operation in 3 and D (ie automatic shifts up and down). Downshifting to 1 manually gets you only 1st gear and a good jolt to bolt. I usually wait until 3 mph or less before downshifting into 1 for any reason. In an emergency, you'd do what you have to do. So my normal options for a warm-up would be 1 (20 mph/2000 rpm) or 3 at 40 mph or higher (2,000+ rpm). I prefer the 2nd one. The owner's manual warns you not be >38 mph in 1st gear. First gear normally shifts out at approx 10-15 mph under normal driving.

 

[bobbydavro]

Originally Posted By: Shannow
Following on from this, the idea of using light load to more rapidly warm up the engine (rather than idle), and my Poohpooed "Italian Tune-up" thread where I can get the Caprice oil temperature to 135C by holding it in "2" at highway speeds.

http://ogst.ifpenergiesnouvelles.fr/articles/ogst/pdf/2013/01/ogst120033.pdf

Figure 3 shows the European warmup drive cycle, and Figure 4 a comparison of a regular IC engine, and a hybrid attacking the cycle.

Hybrid does (as they do) uses the engine harder in the early part of the cycle (if you've driven one, you'll know that they are straight into it), then has a period of electric only.

The initial hit, the metal, the water, and the oil all increase in temperature quite rapidly compared to the IC only.


They need to provide details of what they use car. From testing a prius (parrellel hyrbid) and an insight (series) I can tell you they take much longer to warm up. A prius especially, these only hit 50C oil temps by end of NEDC and at a lower warming gradiant than a Full IC car.

Insight engine is always running, runs only a little cooler due to the IMA. As the rest of the post states though, engine speed is critical and some of these hybrids are very long geared.

 

[Gasbuggy]

Shouldn't the oil weight used be listed in the chart? Wouldn't different weight oils produce different results?


As for cold start losses, I wonder what how 5w30 vs 5w20 would look compared to 5w30 vs 0w30.

 

[Shannow]

Originally Posted By: Shark
Shouldn't the oil weight used be listed in the chart? Wouldn't different weight oils produce different results?


As for cold start losses, I wonder what how 5w30 vs 5w20 would look compared to 5w30 vs 0w30.


Should be, but is all I could find...rest assured, I'm still looking for same.

But you CAN get a feel for the numbers using a journal bearing calculator, and putting in the viscosities (should be high shear really) of the two oils at the temperature you want to think about.

http://www.tribology-abc.com/calculators/c9_3.htm

 

[Garak]

And, as you point out, it isn't just about cold weather, almost all 30 grades, aside from HDEOs and monogrades and Euro grades, on North American shelves will be Euro grades. I'm sure one of the get out of jail free cards would also be shorter OCIs, but you indicate that may not be completely helpful. Now, how do ACEA A1/B1 A5/B5 compare with respect to deposits, since ASTM D7320 isn't used?

In addition to my previous comment about some oils not being offered in the States, there are also some, that while available down south, are primarily offered up here, or at least squarely aimed at us. Petro-Canada's conventional 5w-30 is a good example.

 

[Joe90_guy]

Virtually all so-called Euro oils are put through both the US API tests as well as the European ACEA tests. This has been the case ever since ACEA first came on the scene twenty years ago. I'm not sure what the logic of this is as there are virtually no big Chevrolets or Dodge Rams pootling along Guildford High Street! However all Euro oils will have been put through the Sequence IIIF/IIIG at some stage of their life.

Euro SN/A1/B1 and SN/A3/B4 5W30's tend to be better that US 5W30's in all but one respect. Euro 5W30s are invariably Group III synthetic. There are no Group II 5W30s is Europe (thank God!). They are generally made with 22 SSI VII (as opposed to the 50 SSI ones used in the US) because of the need to meet KO30 shear specs. Also, because they are formulated from the outset as dual-use PCMOs (ie to be used for both gasoline and diesel), they tend to contain more DI than their US counterparts. All oils must meet a 13% min Noack spec and are often well below this number. A1/B1 and A5/B5 oils do need to pass the ACEA fuel economy test but importantly not the API test. The MIIIE test really belongs in a museum but its pass rate is set 'sensibly' unlike the API fuel economy limits which aren't. As such, Euro oils don't exhibit the CCS distortion that plagues US oil.

Although I can't say for certain, I'd guess that US oils on the whole are marginally better on fuel economy that their Euro equivalents but, as I've said before, a price is paid for that particularly with Group II 5W30's. I have also said before that the needs of the OEMs and the needs of the oil producers are not necessarily what the consumer needs. IMO, nothing illustrates this better than US Group II 5W30...

 

[Garak]

I can't speak for a lot of Euro oils, but every A1/B1 A5/B5 oil we get here also meets SN/GF-5, for obvious reasons of marketing usefulness here. An A5/B5 lube certainly is "enough" for most North American applications, but we have those calling for SN/GF-5 or dexos1 or so forth. With respect to the dual use, well, the truest dual purpose oils in North American and North American Japanese applications (in that an oil could meet a current OEM manual specification for both a gasser and a diesel) disappeared a while ago, with a couple weird exceptions.

We have seen some Asian vehicles here permit 5w-40 in SM or newer, along with ILSAC stuff. My G37 does mention SM and GF-4, but only requires the API certification in SM or newer, without requiring the GF-4, so Delvac 1 LE 5w-30 CJ-4/SN E6, E7, E9 would fit the specifications, by my reading.

 

[camrydriver111]

Interesting points.

I wonder if the oil change culture has something to do with it. In the US people used to change oil ever 3k mi and now every 5k mi. Which is better than 3k, but still very short. In Europe what is the most common OCI? 12k mi? If long drain intervals were adopted in the US the oil specs would have to change.