Originally Posted by dnewton3
The whole topic of high wear at start up is total bunk in today's engines.
Macro data shows it's an overblown topic. There's zero proof that it's an issue, and actually hasn't been for many, many years.
There are short-trip commuters that see lots of cold start cycles and they might have 5x the starts that my car sees (I typically only start it 2x a day; once in to work and once home - 30 miles each way).
Are their wear rates 5x mine? No way in Hades.
We had an 1995 Villager back in the day; got it new and ran it to 245k miles. Ran UOA experiments on it trying to understand how OCI duration and use affect wear. It was the wife's van and when the kids were young it was the perfect example of the quintessential soccer mom ride. Short trips, lots of cold starts, etc. It should have been the perfect example of high-wear, if you believe the oil companies and the owner's manual (3k miles for "severe" service were the recommendation). I wanted to experiment, though ... actually started moving out to 5k mile OCIs; no resulting wear issues. Then 10k miles; still no wear issues. Ran some 15k mile OCIs; again no issues. The wear rates were coming down as the OCIs went up. And ... We would take it out to AZ from IN every other Thanksgiving to see the in-laws. Long hauls of 12 hours at steady state; often a 5k mile round trip with all the various side trips of sight seeing. Guess what ... ???
The wear rates never budged; they were what they were. Didn't matter than I ran longer OCIs. Didn't matter than we change operational patterns. The wear rates were fairly steady. There is always variation involved; things are not totally stagnant. But the amount of "normal" variation FAR exceeds the variation from the type of service factors typically induced in use. Life happens, and the engines generally don't care. They shed what they shed, and you're not typically doing much to alter it.
In all the macro data I have, there is zero proof that staring an engine repeatedly makes for a lot of wear. That might have been true 50 years ago when oils were not great and manufacturing of engines was not not great in terms of tolerance controls and machined surfaces. However engines made in the last few decades, as well as the improvements in lubrication, just make this a non-issue; it's a topic that is based in the same age-old rhetoric as is the 3k mile OCI.
If someone has proof (real world data that is not just hearsay) I'll entertain the conversation. But all the facts I have seen show it's a moot point. After all, I have over 15,000 UOAs from all manner of engines and applications; cars, trucks, tractors, generators, etc. Use in FL, AK, AL, CA, MN, ME, TX, AZ, etc. You name it, I've probably got a UOA that represents it well. And the data tells me that multiple starts does NOT induce a shift in wear rates that is discernible in the grand scheme of use. There are a few exceptions I have seen, but even the shift in wear is not enough to make a mountain out of the mole-hill. I've seen wear rates go up as much as 50%, but you have to keep that in perspective ... when an engine averages 2ppm/1k miles, then the use pattern shifts to 3ppm/1k miles, it's not like that engine is suddenly going to blow up, or fail in the next decade. Wear rates today are so low on most engines that even major shifts in wear (again, these are rare) still do not result in wear rates high enough to be of any concern whatsoever. Your car will either rot or be destroyed in a wreck far sooner than the engine will die from wear cause by start-up.
I've said it a few times, startup wear gets blown way out of proportion here. With over 15K UOA's I'd say you have more than enough to prove your point.