Is it still a good idea to take your car out on a highway and drive it fast every once in awhile?
Was it ever a good idea? Never heard that one.
Same here.
It is recommended a car gets driven a few miles if otherwise sitting around. This should be done every few weeks in freezing weather and at least monthly in warm weather.
Some people believe this should occasionally be done to “remove the carbon” that builds up on the pistons, cylinder walls, valves, etc. I am not sure how valid this is for modern internal combustion engines.
Having said that, getting the engine up to operating temperature helps to drive off moisture that can accumulate after sitting for several weeks.
You can do that in neutral in your driveway. I suspect those people feel they just need to rationalize a reason beyond “it’s fun” to speed. I doubt the cops will buy it.
I’ve never seen a specific speed that was required but I never got the impression that you needed to go well over freeway speeds to get the desired results.
My FIL, a retired mechanic, told me this years ago. Whether it still applies to modern vehicles I dont know. He also said the bit about gettting the engine and drivetrain up to operating temp to remove moisture that can accumulate. I responded something to the effect of:
And he pointed out that the transmission and differential needs to heat up as well. I’m not sure I buy this (on older 4x4’s the front axle could be “unlocked” at the hubs so in 2wd mode the front differential was not turning and thus it didnt heat up) but that’s what the pro said, so I still make sure to drive all my cars enough that I go through a tank of gas every 3 months or so and at least a couple of times in those 3 months I take them out onto the the freeway for a while to make sure everything is good and hot.
Ah, the Italian Tune-up…
I’d never get my ancient TVR (1990 Ford V6, EC-IV injection, decatted), through its annual MoT emissions test without it!
People who run cars with diesel engines and do a lot of short journeys (commuting) are advised to take them for a run at least fortnightly to allow that DPF to do its work.
These three things often go together; possibly because for many people, the first is the easiest and/or most convenient way of accomplishing the second & third.
I have certainly heard it (don’t remember where); and, like @running_coach, heard (or possibly just assumed) that the point was to get it up to highway speed.
Which is longer, a few weeks or a month?
FWIW:
My 1998 work van doesn’t get driven for several months in the winter because most likely the only reason the body is still in good shape is because it doesn’t get exposed to the salt on the roads.
About every three weeks I run it a while to keep the battery charged. (Newer vehicles may need this done more often as they tend to have more drains on the battery while turned off. My 1950’s tractors don’t need it done at all; when they’re off, everything’s off.) I also move it a few feet back and forth and set and release the emergency brake so nothing seizes up. The engine does get up to normal operating temps. I’ve been doing this for years, no problems.
It’s also advisable to run your engine hard when you have a boat. The usual scenario:
Boat with (in my case, diesel) engine sits in marina 99% of the year. Weekly, it needs to be checked. So I visit the boat, run the engine a bit, charge both batteries (house and engine batts), check for damage / leaks / etc. Just sit for a while on the deck, vibing in the cool fog of the marina.
Then, after maybe 20 minutes, both batts are charged enough to stay healthy for at least another week or two. Yes, I ran shore power to the boat for the shore battery when I could. But I recollect I also had to do a weekly charging using the engine.
Friend advised me that these short runs of the engine, just enough to barely warm up, left a lot of carbon, so I’d either have to take the boat out every once in a while and run the engine hard, or just “tow the dock” and do it in place, to burn off the accumulated carbon.
Few weeks would be 3 or less. Depends on your battery and car, not an exact science by any means. So few weeks < a month.
The context I always heard was for people storing classic or other cars for prolonged periods. Some folk thought it was enough to just start the car and let it run for 10-15 minutes every couple of weeks. As I recall, the majority opined that it was better to drive somewhere for the same amount of time and - if possible - at speed or up hills. Of course, you have to weigh whether it can be done free of ice/salt…
I’ve never heard this advice as implying that you need to go over the speed limit. In fact, I’ve usually heard it as “take the car on the highway” rather than “going fast”. Where I live, the speed limit on non-highways is normally 25 mph - and I could go weeks driving within getting above 15 mph. I suspect that’s not true in most places in the US.
Lots of “I’ve heard…” here, but what’s the straight dope? Is carbon buildup a real thing these days, is it a problem, and will driving on the freeway reduce the problem? Are there other, factual reasons to do what the OP asks?
These days, most of the carbon buildup is on the backs of the valves…
If true, that would still interfere at least some w engine breathing & efficiency. So ideally the build-up would be removed. Does running WAG 20 miles at highway speeds accomplish that? Hellifino.