Shutting your car off before it's fully warmed up

Status
Not open for further replies.
Originally Posted By: tmorris1
Originally Posted By: Benzadmiral
In the cooler weather (rarely cold, down here in The Inferno), I will occasionally run the long way to work: 2-3 extra miles northward on the expressway, then back down a well-paved major street. It makes for a 15-mile rather than 9-mile commute, with a little more time at a steady 60 and then at a steady 35 without lights. Partly I do it to get the engine a bit hotter, and partly for fun -- I'm experimenting to see if it brings my average gas mileage up a fraction.


Your average mileage may go up, but you are still burning more gallons of gas than you would on the shorter trip...


Yeah, I know -- that's why I do it only occasionally, in the good weather.
 
Originally Posted By: tmorris1
Originally Posted By: oilyriser
In the cold winter, after several quick starts and shutdowns, you may find your car with no compression as the gas has washed all the oil off the rings. Then man has to serve machine for a while.

What do you drive. a Model A???


My first smile today......we do tend to sweat the details here.

One of my biggest breakthroughs was when I had engine work done and they replaced my 5-20 synthetic with 5w30 conventional
smirk2.gif

I was strong though and went 1500 miles on that barbaric dino before changing back. Can you believe that car still runs....
wink.gif
 
Shutting the engine off before it has warmed does cause condensation to form, especially in the exhaust. I have a friend who owns a late model Dodge Ram (Cummins). He primarily uses the truck to tow his race car and other toys around. He frequently starts it briefly to move it out of the garage in order to have room to work on his race car, etc. Last summer (the truck was about 4 years old) his exhaust literally fell off, rotted from the inside out.

Of course, he took it as a sign that he needed to get larger diameter piping.
 
Originally Posted By: Bircsbor
Shutting the engine off before it has warmed does cause condensation to form, especially in the exhaust. I have a friend who owns a late model Dodge Ram (Cummins). He primarily uses the truck to tow his race car and other toys around. He frequently starts it briefly to move it out of the garage in order to have room to work on his race car, etc. Last summer (the truck was about 4 years old) his exhaust literally fell off, rotted from the inside out.


I have the same problem with my Dakota, caused I've been told by short trips. I was told to drive it more to make the exhaust last. However, when I figured the cost of driving it more it is cheaper to spend $150 on muffler and tailpipe than it is to do all the driving.

John
 
Originally Posted By: CATERHAM
Ofcourse the solution today would be to choose a plug-in Hybrid vehicle and not start the engine at all.

I know this is off topic, but this comment got we wondering? How do you get heat in the winter on a hybrid if the engine isn't running? Do they have electric heat? This would kill a battery very quickly.
 
Originally Posted By: John_K

I have the same problem with my Dakota, caused I've been told by short trips. I was told to drive it more to make the exhaust last. However, when I figured the cost of driving it more it is cheaper to spend $150 on muffler and tailpipe than it is to do all the driving.

John


You, my friend, are a wise man!

My town is not much more than 4 miles across and there's pretty much nothing else for nearly 100 miles around it so nearly all of my driving is 5 miles (to work) or less, and sometimes a lot less. Every few weeks or so I might hit the highway heading out of town for a few hundred mile road trip, but that's the exception, not the rule. This is the reason I've started doing used oil analysis on my cars, to see what kind of effect it has on it and I'll make the best decision based on this and other information I can come up with.

If I made sure that each of my cars I own was driven at least one trip of 15 miles per day (minus the maximum 5 miles that I'd be driving anyway) that it's driven (maybe 300 days per year for each car) then I'd be adding about 3000 miles per year per car. Even if you use a relatively low $.20/mile that's $1200 extra I'd be spending per year! I could change a lot of oil for $1200! Shoot, I could buy a beater car for the commute and just save my newest car for the track or road trips!
 
Hi tmorris1,

" how do you get heat if the engine isn't running in a hybrid "

I'm not sure but I think in a regular non plug-in Hybrid the answer is you don't. Besides, if you're only driving a couple of miles you're not going to get any heat in a gas powered car anyway.
 
I always try to get my truck fully warmed up. It usually doesn't take long, just a few miles. It may be wasteful and pointless, but it gives me peace of mind, and I like driving my truck anyway.

Originally Posted By: tmorris1

I know this is off topic, but this comment got we wondering? How do you get heat in the winter on a hybrid if the engine isn't running? Do they have electric heat? This would kill a battery very quickly.


You don't. In my dad's Civic Hybrid the heat and A/C cut off with the engine. If you tap the gas pedal the engine will kick on and stay running until the next time the car stops.
 
The funniest story was about school buses up north that ran on natural gas. They would quit running, exhaust systems totally plugged with ice.

My Subaru is picky about multiple cold restarts. Maybe the horizontal cylinders allows the gas to pool on the sides.
 
I have done many trips less than 1 mile at -20C or sometimes even colder. I frequently go out for lunch which is less than a mile each way. I have started my car at -35C, not plugged in, and driven 1 mile and parked it.

Up until 2007 all I ever ran was name brand 5w30 conventional (Pennzoil, GTX, etc.). I typically change the oil every spring and fall with anywhere from 4000 to 6000 miles OCI. I get about 5 years on a muffler and I have put 230,000 km on several vehicles with no major issues.


I watch my PCV valves closely and change out when needed. I have had the PCV plug.
 
Last edited:
Originally Posted By: OrdnanceMarine
Originally Posted By: John_K

I have the same problem with my Dakota, caused I've been told by short trips. I was told to drive it more to make the exhaust last. However, when I figured the cost of driving it more it is cheaper to spend $150 on muffler and tailpipe than it is to do all the driving.

John


You, my friend, are a wise man!

My town is not much more than 4 miles across and there's pretty much nothing else for nearly 100 miles around it so nearly all of my driving is 5 miles (to work) or less, and sometimes a lot less. Every few weeks or so I might hit the highway heading out of town for a few hundred mile road trip, but that's the exception, not the rule. This is the reason I've started doing used oil analysis on my cars, to see what kind of effect it has on it and I'll make the best decision based on this and other information I can come up with.

If I made sure that each of my cars I own was driven at least one trip of 15 miles per day (minus the maximum 5 miles that I'd be driving anyway) that it's driven (maybe 300 days per year for each car) then I'd be adding about 3000 miles per year per car. Even if you use a relatively low $.20/mile that's $1200 extra I'd be spending per year! I could change a lot of oil for $1200! Shoot, I could buy a beater car for the commute and just save my newest car for the track or road trips!


Are you kidding? One oil change alone is the price of a full tank of gas, especially if you're running synthetic. This doesn't count the exhaust rusting or the increased engine wear. It take about two minutes for my car to go from 140 to 200, which is all the extra driving I needed to get it fully warmed up.

And if you have a car with sentimental value all the more reason to serve the machine. Serving machines is like the hobby of half the people on this site.
 
Quote:
It take about two minutes for my car to go from 140 to 200, which is all the extra driving I needed to get it fully warmed up

Just because you get the temp to 200 doesn't mean you are going to burn off condensation in the oil. You need a sustained period at operating temps to get rid of all the condensation. Also in the 2 minutes it takes to get the water to 200, your oil temp is going to be far less than that. It takes several miles of driving to get the oil up to temp.
It is more of an issue with the exhaust than the engine. As long as you get the thing out for a long trip every couple weeks you are fine as far as the engine goes. Oil is good today and at worst you change it a little sooner in the winter. I take lots of short trips 2-4 miles in below zero temps and my used oil analysis come back with no water in the oil and both of my vehicles are 10 years oil on the original factory exhaust ( I think they are stainless though). My 2 cents.
 
If someomne seriously drove only 1/2 mile twice a day, maybe once a week it would be justified to run the car around a few extra minutes, not every day. It would not make practical sense to change your daily routine around making the car "happy".
 
Correct me if I'm wrong... moisture condenses when the oil cools no matter if you just finished a 200 mile highway trip, so you're always going to have a little in the oil. It's running the car on short trips without raising the temps enough to burn off the existing H20 that can have you lugging around a bunch of water in your sump after a while.
 
on a 40 degree morning, my srt4's oil takes a 3 minute idle, a 1 mile 25mph trip through the neighborhood, and 12 more miles at 55-60 down a highway to reach 195*F. Coolant will be at 195*f around the 4 mile mark. we have coolant/oil heat exchangers
 
Status
Not open for further replies.
Back
Top Bottom