Driving an engine when it’s literally dead cold when the fuel mixture is richened because of the cold engine or letting the vehicle run for maybe 2 to 3 minuites tops to let the engine warm up which allows the engine to run at less rpms due to the fuel mixture not being so rich? I went out today and started my 2009 Camry, let it run maybe 10 to 20 seconds, put it in reverse and doing so the engine was idiling higher about 700 rpms more. I then put it in park, let it run for about 2 minuites and then engine was only at about 900 rpms.
Sitting for two or three minutes wastes more gas.
It is most efficent and good for your car to let the engine idle only long enough to run reliably, then drive at less than freeway speed until the warms. Driving a cold engine hard when it is cold can cause a lot of engine wear.
As for your specific question, it will depend on the car. The answer will be different for fuel injection vs carb etc. But it is not as important that protecting the engine which will cost more and cause more pollution in the long term.
You might as well be moving while the engine is warming up. All cars get zero miles per gallon while parked and running. Besides, your engine warms up quicker when it is doing work.
Don’t warm up your car by leaving it idle. The gas savings that you may achieve will quickly be negated if someone breaks your window and takes off with the car.
Sitting still waiting for the engine to warm up uses more gas than driving the car gently as the engine warms up.
The engine warms up more quickly if the vehicle is driven.
“As for your specific question, it will depend on the car. The answer will be different for fuel injection vs carb etc. But it is not as important that protecting the engine which will cost more and cause more pollution in the long term.”
This is the one I most agree with. Some vehicles we use are absolutely terrible mileage wise and very inefficient until fully warm as much as 30 minutes later. If you live next to a highway and can’t drive slowly, you’ll have to wait longer. There is an advantage to your FWD Camry here over RWD vehicles of all types in warm ups. So minimal time is fine, and that varies a little with ambient temperature as well.
Good question with winter comming on.
This is the one I’d most disagree with. Idling never saves gas, FI or carb. Also it doesn’t matter if you have to be on the freeway within a half mile or less. I start up and put it in gear immediately, within one minute I’m up to 50 mph. Been doing it for over 40 years in all my cars, the current one has over 200k with no problems.
Some vehicles we use are absolutely terrible mileage wise and very inefficient until fully warm as much as 30 minutes later. If you live next to a highway and can’t drive slowly, you’ll have to wait longer.
It should not take 30 minutes of driving to warm an engine (idling is a different issue, and IMO should be be used to warm up a car)
If you live next to the freeway, you don’t need to use the nearest entrance, just take a surface street to the next entrance.
While I tend to idle for a few seconds and then drive slowly until a car warms up, I will defend anyone who wants to let their car idle for 5-10 minutes so they can get into a warm car.
It seems like there’s an abundance of opinions about wasting gas if you let your car warm up for more than 10 seconds. Yet no one cares about the gas you use on that 2nd trip to the store for the item you forgot, or about the gas you use on that Sunday drive.
There is one other thing to consider; higher rpms reduce combustion blow-by. If you sit and idle to warm up, you’ll get more particulates in the oil and pollute it faster. Brief warm up and drive off at no more than moderate speeds/loads and it’s better all the way around.
If you regularly operated a tractor, diesel plow truck or other heavy equipment, you may agree with me. Too much $$$$$ involved in replacement cost to not warm up vehicles with multi task fluids (hydraulics). That vehicle “warmed up time” is on an individual basis is your premise that I was agreeing with other examples. A tad frustrating. That excessive idling wastes gas is irrefutable but a sacrifice we vehicle particular operators make regularly. I implied, it does not apply to a “Camry” and Camry FWD like vehicles.
If you live next to the freeway, you don’t need to use the nearest entrance, just take a surface street to the next entrance.
We’ll have to agree to disagree on this one as at some point, driving around on a side street just to warm drive train fluids may be worthwhile with some vehicles but equal to idle time on fwd car if your not fortunate enough to have immediately access on ramps to give you options. I just won’t drive my vehicles at higher speeds til they’re ready, and though your option is sometimes feasible,our individual local and needs may determine differently. A longer warm up time than 30 sec may sometimes be necessary. How can one disagree ?
A 5 star observation if I’ve ever heard one…
Agree, and more damage is done to the exhaust system.
The question was about what was best for mileage, not for the owner. Frequently, the two are not the same. If the owner wants to warm the car so that they will be more comfortable, then that is what they should do. Gas is wasted for worse things to be sure.
However, if the owner wants to warm the car because they believe it will make the car last longer or that it will save gas, then they are mistaken.
And you live where ? Try that when it’s -30 degrees.
Ditto. Driving away with an engine that cold will reduce the life of the engine and will increase emissions. At -30 deegrees the internal parts are not at their optimal shapes, and in addition to the direct effect of that on wear that also allows increased blowby, contributing to dilution of the oil. And normal weight oils turn to molasses. Extreme cold climates need block heaters or lower raditor hose heaters…plugging the car in at night is the best solution.
And your butt will freeze! Trust me on this… my years in North Dakota left me with lasting knowledge on the effects of extreme cold on cars.