Is 'most wear at startup' a myth?

[Curious Kid]

The "designed to start and go" as mentioned concerning modern fuel injection, is an interesting note. If I recall correctly, the immediacy of an engine so equiped, to fire after initiating the starter, raised concerns about mechanical stresses from less oil circulation or pump-up and any relative wear to come of it. Just because fuel is immediately introduced and amply supplied to allow for seemingly efficient engine operation, it has little if anything to do with the lubrication side of things.

A bonus though from the use of electronic fuel injection is that with such precise fuel metering, one is less apt to contend with flooding of the cylinders and high fuel dilution of the oil...assuming everything is in good working order.

- perhaps.
I will say the discussion is good, and what references that do come along are interesting...but could one be more specific to back one's explaination as to provide case examples? I'm not trying to be a hard***, and admit that most of what I add wouldn't be do the the lack of hard data, but sometimes I just feel one is prying the sense of another, and doing little more than going in circles. Just a thought anyhow.

Carry on.

 

[Fastride95]

Curious Kid raises a good point. It makes sense that a modern computer controlled fuel injected engine in good tune would minimize the amount of fuel dilution even during extensive idle from a cold start.

However, I remember Dr. Haas mentioning that one of his Ferraris had high fuel dilution from repeated short trips and even my Honda Prelude VTEC (by no means a Ferrari level car) tends to run rich for the 1st few minutes. Analysis shows that without occasional sustained higher RPM runs it will continously dilute the oil with gasoline. The car is well tuned and maintained but after a month of short trips (10 - 15 minutes to work depending on time of day + lunch runs, etc.) I pulled the dipstick and the oil smelled like gasoline! So for some cars fuel dilution is still a problem that contributes to increased wear depending on how it's driven.

On the other hand, I now drive a '95 Ford Aerostar with the 3.0L for work as a sub-contractor. It gets beat up on the short trips and the Honda sits in the garage for sunny long trip go-somewhere days. The van is always idling with nothing but short trips and while I haven't done a UOA on it I have yet to see any evidence of fuel dilution using the smell test. I should mention that I don't let it idle long at cold start but it does idle a lot while waiting for a customer so I can have A/C or heat, etc.. This is in North Florida so the warmer temps certaintly make a difference.

Tom

 

[Dad2leia]

I have smelled the oil on my CR-V, and no real pronounced gasoline odor. Usually it smelled like used oil does, just used, not burnt, fuel like, or strange (hard to explain). They put the 2.4 L i-VTEC under the hood, so it is pretty high tech, and really is quiet on a cold morning start up.

Granted, I've only about 2500 miles or so on the oil, but I do keep tabs, particularly in the winter due to the cold.

 

[Leo]

I have a wideband O2 sensor, and I think the 'richness' during cold starts may be over emphasised. When I first start my cars in the morning, the AFRs hover around the mid 12:1 which isnt all that 'rich'. They quickly return to 14.7 (stoichiometric) in roughly 1 minute, or even faster if the car is driven off ~10 sec after startup. Thats not a lot of time for the fuel to seriously contaminate your oil!! Although my cold starts are about 15C, people in much colder climates, YMMV.

 

[99]

The "start and go" statement I made refers to the modern fuel injected engine's ability to be able to be driven off immediately after starting due to the inputs of the engine's sensors and the computer's ability to intrepret them real time and adjust the fuel mixture accordingly. This means the engine will run as seamlessly frozen cold as it would fully warmed up. With that mouthful said, a fuel injected engine will warm up much faster if driven off then if allowed to sit and idle to build up heat. The faster you can build that heat, the less the engine wear will be. Back in the day, the carbureted engines couldn't accomplish this nearly as well.....those of us old enough to remember carburetors know how tempermental they were on cold days. Fuel injection did away with all that nonsense and gave us better power, torque and fuel economy in the process. Gotta love technology...sometimes.

 

[the_oil_dealer]

within 4-5 minutes my cars temp guage is smack dab in the middle, and i use this as comfort to boot the rest of the trip to work. I know oil takes a bit longer to heat up, but with the way i drive, its probably REAL quick... I find myself going 180-220km/h almost every morning on the last stretch, and that has cruising RPMs in 5th gear at about 5800rpm, not to mention the acceleration up to that speed in 4th peaking the tach at 6800 or so.... this commonly occurs just under 10 minutes after start up. Overal trip duration no longer than 15minutes.

 

[Dad2leia]

Nothing gets the blood flowing like a nice, leisurely drive to work in the morning...

 

[AEHaas]

I hope all your cars have oil temperature gauges. Water gets up to operating temperature in 2 - 4 minutes. Oil takes 15 to 20 minutes, sometimes even longer.

Stop and go traffic back and forth to school and the ball field are hard on the engine and the oil because they never get up to full operating temperature.

The newest formulations include additives that work in this "cold" start up period for just this reason.

aehaas

 

[vwoom]

Read this:
Effect of Break-In and Operating Conditions on Piston Ring and Cylinder Bore Wear in SI (Spark-Ignition) Engines, Schneider et al (from SAE):
The rate of wear is much higher within 15-20 minutes of start-up than after reaching normal operating temperature. The initial start-up time period (first 20 minutes) result is 100 nanometers of wear whereas the steady state wear rate was only 4 nanometers per hour thereafter.

Read the original article it may shock some people.

aehaas

..which is why I do not rev my 1.8T anywhere past 2,000rpm within the abovementioned period until temp gauge moves halfway to or at regular operating temp of 190F...been doing this engine care habit since car was new in 2000.

A good 2mi side streets worth of warmup driving from home, before pressing the metal to the pedal on 10fwy.

 

[Dad2leia]

Leo, what kind of engine is it? I know about the Honda engines in particular. Most of them run so lean most of the time, they are just a few tenths of a ratio from stalling, hence the fuel economy. One engine that I heard about in class in particular tried a 21:1 at one point (talk about a candidate for pinging and detonation issues!!!)

 

[Curious Kid]

Quoting AEHaas
"The newest formulations include additives that work in this "cold" start up period for just this reason."

That's good to hear AEHaas. May I ask where you came across this info. as I have asked for the like on another thread, as many of the additives are heat activated?

Thanks.

 

[Gary Allan]

quote:

---

..which is why I do not rev my 1.8T anywhere past 2,000rpm within the abovementioned period until temp gauge moves halfway to or at regular operating temp of 190F...been doing this engine care habit since car was new in 2000.

A good 2mi side streets worth of warmup driving from home, before pressing the metal to the pedal on 10fwy.

---

Vroom ..that's 15-20 minutes til full oil temp. Some of you VW/Audi people have exchangers that shorten the oil temp upramp ..but the engine is marginally warmer. It still takes probably 10 miles or more for you to "warm up". Coolant is only half of it ..and in your case ..so is oil temp. You're providing more thermal backpressure that is normally shunted to the rad ..and is absorbed by the oil from the heating of engine parts that are subjected to combustion temps. Hence instead of 70F oil sapping the btu's migrating from your pistons and sending it into never never land ..the excess btu's that your coolant sends to never never land is sent to your oil ..effectively preempting the normal oil warming. It, at best, gets in the way of the escaping btu's from the combustion process, allowing a shorter warm up time. It in no way assures that you're "warmed up" in spite of normalized coolant and oil temps.

 

[AEHaas]

The best single source of information right now is right here on this site:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=forum;f=21

If you read SAE papers and go to meetings, the race track, discuss things with mechanics, engineers, chemists in the field year after year then you tend to pick up a lot of information. Not all of it is correct though.

Oil is like medicine. There is a ton of information out there but no one person knows it all. The best you can do is talk, read, discuss and put a lot of time into it.

I used to quote a bunch of papers for most of what I was saying but it is just too much work for me to keep it going, sorry. I like to go with the facts when possible.

Good Luck!

aehaas

 

[moribundman]

Coolant on my Audi reaches operating temperature within about 3 miles or 5 minutes, pretty much independent of ambient temperatue (mild climate

)

At city speeds, it takes the oil about 30 minutes to reach its normal operating temperature of ca 200 F. I don't drive the car hard until the oil is up to 175 F and until then I keep it under 3k rpm.

At highway speeds, oil operating temperature is reached in about 8 minutes.

BMW used to state that an engine had fully warmed up after 45 minutes at highway speeds.

 

[RickRS]

Holy cow, I'm doomed!

Got a '00 Miata two years ago with 29,000 miles. Most fun I had in a car, love it to death.

Problem, it's my daily driver, and the drive to work is only 3 miles, in town, takes about 10 minutes (stop lights). Annual mileage is 5K, almost all in town, short distances, stop-and-go.

I'm using Mobil 1 for this car. Mazda recommends 10W-30, which I been using. A recent post on the Miata.net site linked to Dr Haas' report on light weight oils suggests that dropping to a 5W-30 or 0W-30 would be a better ideal. So I'm seriously thinking of using 0W-30. I'm in NW Florida, and winter is mild, with few weeks with lows below 30F, and record lows having only gotten to about 10-12F. Summer temperatures highs are 90-95F, and record high is maybe 100-105F.

So what would the good Doctor, or any of you, order to prolong the life of this fine little car I seem to be driving to an early grave?

 

[texasproud]

"So what would the good doctor,or any of you, order to prolong the life of this fine little car that I seem to be driving to an early grave?"

IMHO, the incremental difference in wear between oils,driving styles and warm-up periods (in Ft Walton Beach !) is just too minute to cause undue concern for 99.9% of the motoring public. What good is it to own a car that is "fun" to drive if we grieve over 10 nanometers of wear ? Use the recommended oil, changed at prudent intervals and enjoy doing what the car was intended to do ....be driven.

 

[Gary Allan]

quote:

---

Holy cow, I'm doomed!

---

Time is on your side in this use. It will be an antique before it's even close to worn out.

You're not doomed (I assume that this was said tongue in cheek). You are subjecting your engine to no more "abuse" than anyone else who is a short trip type. Although we look at this wear, what I consider mostly unavoidable, as "terrible", it's all "normal". Something like disk compression/erosion.

I would think that the good doctor's writings would suggest a 20 weight for your service. It will be a 30 weight (probably) for all, or the majority, of your drive ..maybe a 40 weight in the colder seasons.

 

[RickRS]

Yes, take my "statements" as either tongue-in-cheek or overly melodramatic. I would expect the engine to do 100k+ easily, as prior vehicles have with my typical upkeep, and at my current 5K annual rate, that's 20 years.

As far as it goes, my annual mileage is low because I'm so close to my job. I drive the car as much as I want/need. It's no garage queen. Texasproud's wrench wacking greamlins aren't necessary (but I don't mind

), as I intend to enjoy my car. Althrought I AM using syn oil (M1) for the first time in a vehicle, in hope that it WILL add to a trouble-free life.

But this thread continues to raise the question that maybe I could tailor my oil, as suggested by Haas in some of his other threads, to minimizing some wear because of my high "cranking vs. driving" ratio.

 

[Pitbull]

RickRS, I have the same deal you have just different part of the country (SW Utah, high desert 5000 ft.) have a 1999 Landcruiser with 58K miles and a Nissan 350Z with 18K miles. Put about 5K miles on both. Drive 1 mile into town, turn the car off, drive another 2 blocks stop turn the car off, drive 1 mile back to home. About 2-3 times a month drive to St. George Utah (85 miles oneway). I run Mobil 1 5w30 in the LC and Mobil dino 5w30 in the 350Z (Nissan does not recommend synthetic oil in the Z and other owners in the Z forum state that the engine uses oil when they have used a synthetic oil. I figure the engines will be fine, I'm worried about wearing out the starters

 

[Gary Allan]

quote:

---

But this thread continues to raise the question that maybe I could tailor my oil, as suggested by Haas in some of his other threads, to minimizing some wear because of my high "cranking vs. driving" ratio.

---

Although I don't share the good doctor's view of lighter weight oils reducing wear directly due to simulating heavier oils earlier in the warmup event, I do think that on some "second or third order" that they can reduce wear. You will require less hp to pump them. This, in any mode (cold start, open loop and closed loop), will reduce the severity of otherwise unavoidable wear.

It makes little sense to use a 30 weight that never reaches the status of a 30 weight due to lack of reaching temp.