Warming Up A Piston Engine Is Harmful (?)
Warming Up A Piston Engine Is Harmful (?)
An article circulating recently cited a Firestone shop and a Toyota dealer saying warming up your piston engine shortens it's life because idling strips oil from the pistons.
They say because the car isn't moving the oil isn't lubricating the pistons.
I wasn't aware of this, if it's true.
Personally, I usually only warm up mine when it's very cold, not only to warm up the cabin or thaw ice on windows, but also to warm up the belts and hoses.
https://www.verifythis.com/article/n...d-d1d56006e5d9
They say because the car isn't moving the oil isn't lubricating the pistons.
I wasn't aware of this, if it's true.
Personally, I usually only warm up mine when it's very cold, not only to warm up the cabin or thaw ice on windows, but also to warm up the belts and hoses.
https://www.verifythis.com/article/n...d-d1d56006e5d9
So I assume they mean there's not enough oil reaching the pistons unless the car is operating at higher rpms?
I don't understand why there's not enough at idle.
Maybe they're trying to say that low oil pressure at idle and higher viscosity when cold means oil is less effective? I mean they also say "cylinders and pistons, components that help the engine move the car". I mean yes, having pistons doesn't *hurt*. Sounds like someone without any technical background wrote what they understood from someone else's explanation.
That's some pretty crappy fact checking... The fact that whoever was in charge of that thought checking in with some random repair shop was worth the time it took to look up the number is telling. Most grease monkeys, like youtube creators, I've met don't have a clue how an engine works, and this is a great example of that. The only way the "car needs to move to get the oil moving" things checks out is if the oil pump is completely clapped out, and only moves oil at higher RPM. Otherwise, this is a complete failure to understand any of it.
More wear MAY occur in a binary/true-false sense if you let it sit and idle, but only because it takes longer to get up to temperature. However, the same could be said in reverse since you're asking more of the engine while it's still cold if you just set out. I believe the current recommendation (which may be where the DOE's statement was coming from) is to just start and go, and with modern (cooling systems/lubrication/emissions/etc.) there's less overall wear, and that's what I do. But if it's super duper cold like it has been here the last few days (highs below 0°F), I'd still warm the car up before I got going, if only to get some heat in the interior plastics before they get jounced around on snowy mountain roads so they don't crack.
Moral of the story, don't believe everything you read/see on the internet.
More wear MAY occur in a binary/true-false sense if you let it sit and idle, but only because it takes longer to get up to temperature. However, the same could be said in reverse since you're asking more of the engine while it's still cold if you just set out. I believe the current recommendation (which may be where the DOE's statement was coming from) is to just start and go, and with modern (cooling systems/lubrication/emissions/etc.) there's less overall wear, and that's what I do. But if it's super duper cold like it has been here the last few days (highs below 0°F), I'd still warm the car up before I got going, if only to get some heat in the interior plastics before they get jounced around on snowy mountain roads so they don't crack.
Moral of the story, don't believe everything you read/see on the internet.
Warmup strategy is HIGHLY dependent on the specific engine design, and its effects CANNOT be measured. This means two things:
1. Any broad "this is what you should do" is worthless, because you can't make broad generalizations.
2. Because the effects of warmup strategy can't be directly measured, there can be no true right or wrong, so it's a ripe topic for dumb people weighing in with their opinions.
1. Any broad "this is what you should do" is worthless, because you can't make broad generalizations.
2. Because the effects of warmup strategy can't be directly measured, there can be no true right or wrong, so it's a ripe topic for dumb people weighing in with their opinions.
its winter and i live in a cold area so i hit the remote start on my dd every morning before i leave for work. i dont like being cold or scraping ice/snow off my car (garage has other car, quad and motorcycles in it). it only runs 5-7min before im on my way and havent had any issues in many many years of driving

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Citing a glorified Jiffy Lube and a stealership as credible sources is along the same lines of logic as saying the tools from Harbor Freight are of industry leading quality and craftsmanship.
couldn’t have stated it better myself, but those people aren’t going to listen regardless so why bother …
but watching the 2022 SEMA vids it looks like HF might be trying to step up their game
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but watching the 2022 SEMA vids it looks like HF might be trying to step up their game

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Last edited by TeamRX8; Dec 28, 2022 at 02:41 PM.
I don't think any of the mentioned agencies, other than USDOE are capable of conducting experiments and publishing any scholarly reviewed article. Citing them is just like citing Wikipedia in your graduate school paper.
Get in the car, start, buckle up, set up phone & navigation, adjust the mirror and seat if needed. Drive easy till the car warms up.
Get in the car, start, buckle up, set up phone & navigation, adjust the mirror and seat if needed. Drive easy till the car warms up.
Fwiw, I started this for the discussion, not that I believed them.
Thus the (?) in the title.
I never heard of oil 'draining' from the cylinders and thought since someone was passing it off as a 'news' article and other sites ran with it, it warranted attention.
I'm in my 60s, I remember working on cars sitting on the fender with my feet in the engine bay.

If it was some new quirk involving modern engines, I wanted to see if anyone else had heard of it
I will continue to warm up my piston vehicles as I always have.
My '95 Hardbody was still running strong at 230,000 miles before it rusted out beyond repair.
Thus the (?) in the title.
I never heard of oil 'draining' from the cylinders and thought since someone was passing it off as a 'news' article and other sites ran with it, it warranted attention.
I'm in my 60s, I remember working on cars sitting on the fender with my feet in the engine bay.

If it was some new quirk involving modern engines, I wanted to see if anyone else had heard of it
I will continue to warm up my piston vehicles as I always have.
My '95 Hardbody was still running strong at 230,000 miles before it rusted out beyond repair.
Fwiw, I started this for the discussion, not that I believed them.
Thus the (?) in the title.
I never heard of oil 'draining' from the cylinders and thought since someone was passing it off as a 'news' article and other sites ran with it, it warranted attention.
I'm in my 60s, I remember working on cars sitting on the fender with my feet in the engine bay.

If it was some new quirk involving modern engines, I wanted to see if anyone else had heard of it
I will continue to warm up my piston vehicles as I always have.
My '95 Hardbody was still running strong at 230,000 miles before it rusted out beyond repair.
Thus the (?) in the title.
I never heard of oil 'draining' from the cylinders and thought since someone was passing it off as a 'news' article and other sites ran with it, it warranted attention.
I'm in my 60s, I remember working on cars sitting on the fender with my feet in the engine bay.

If it was some new quirk involving modern engines, I wanted to see if anyone else had heard of it
I will continue to warm up my piston vehicles as I always have.
My '95 Hardbody was still running strong at 230,000 miles before it rusted out beyond repair.
Some of the other comments seemed a little ambiguous, I just was clarifying my thoughts.
its winter and i live in a cold area so i hit the remote start on my dd every morning before i leave for work. i dont like being cold or scraping ice/snow off my car (garage has other car, quad and motorcycles in it). it only runs 5-7min before im on my way and havent had any issues in many many years of driving
My newer vehicles all rev high when first started, even in warm weather I don't put them in gear until rpm drop a bit under 1,000.
watched a youboob video the other day of a guy who bought a Caprice police car at an auction; had ~82,000 miles on it, but thousands of hours of idle time (it had an idle time logger on it). There’s some formula to convert idle time into mileage. It worked out that the idle time was equivalent to over 200,000 miles of driving. So he tore the engine down to overhaul and modify it. It was nearly perfect inside with very minimal wear. Every indication was that it was 100% original from the factory including the sparkplugs; just oil change maintenance.
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