Fuel Consumption Economics...???

[redyaris]

Originally Posted by Lazarus

Not to average speed but the IRS figures .50 cents a mile.

For the sake of this discusion then; if we calculate speed in Miles per Year then as your speed per year goes up, so does the cost. So if the average speed is 12000miles/year the maintainance cost is $6000.-/yr and if the average speed is 18000mile/year then the maintainance cost is $9000.-/year. does this mean that the increased maintainance cost of speed is liniar? I think not, if we look at tire ware rates I have read that it is as the speed goes up so does the RATE of ware. If we look at the cost per mile of racing then we can see that the cost of speed is more like exponential than liniar, something like the relationship between speed and power. how much does it cost to go 1/4 mile in 10sec?
Thanks for the IRS number it is a starting point, does one of the engineers have a model they use to determin the cost of doing things faster?

[Lazarus]

This thread is making my head hurt.

[dcb]

There's one sure fire way to save tons of money where your car is concerned, and that is being able to fix/mod it yourself.

[Patrick]

I don't think the cost of maintenance, per se, is going to be that much more, if any more, for driving faster. If I drive 100 miles @ 70 mph instead of 55, the driveline still went around the same number of times, the pistons went up and down the same number of times, the tires went around the same number of times, etc. Since we do our oil and filter changes, etc, based on miles driven (or at least we're suposed to), we will pay the same amount for these items at either speed.

[NachtRitter]

I would go so far to say that stop & go driving puts quite a bit more wear on your car than "high speed" (traveling 75 - 85 mph) driving, even though the avg speed is much lower...

[redyaris]

Originally Posted by Lazarus

This thread is making my head hurt.

Sorry for the pain, that was not my intention. what i am looking for is what people have learned hear and there about the benifits of slowing down... if or when you find some interesting study post it here.

[redyaris]

Originally Posted by Patrick

I don't think the cost of maintenance, per se, is going to be that much more, if any more, for driving faster. If I drive 100 miles @ 70 mph instead of 55, the driveline still went around the same number of times, the pistons went up and down the same number of times, the tires went around the same number of times, etc. Since we do our oil and filter changes, etc, based on miles driven (or at least we're suposed to), we will pay the same amount for these items at either speed.

It is true that the number of revolutions over the 100 mile trips is the same whether going 55mph or 75mph the force aplied to the parts at 75mph is greater so the rate of ware will be greater, even though the cost may not show up in one service interval. Many vehicle are seviced with referance to time not distance.

[redyaris]

Originally Posted by NachtRitter

I would go so far to say that stop & go driving puts quite a bit more wear on your car than "high speed" (traveling 75 - 85 mph) driving, even though the avg speed is much lower...

Good point; so unless we include the rate of acceration into the understanding we will be missing something. Then the more force we apply to the variouse parts of the car the fasted they will wear.

[NachtRitter]

That's why there's (typically? usually? always?) two maintenance schedules for cars... "normal" use and "severe" use. Severe use is stuff like driving short distances, stop & go, dusty conditions, extreme cold conditions, etc, etc. It would be really difficult to determine ( I think ) how much of a "benefit" there is to eco-driving vs normal driving from a wear & tear perspective, with so many other factors that come into play.

Take my situation for instance... there are two routes I can take when commuting to work. One is ~75% freeway, the other is 100% surface. I get worse FE on the freeway, but gut feel says it's less stress on the car being able to cruise on the freeway in a single gear than taking the surface route with the more frequent full stops and the associated gear shifts...

[ShadeTreeMech]

Originally Posted by NachtRitter

Take my situation for instance... there are two routes I can take when commuting to work. One is ~75% freeway, the other is 100% surface. I get worse FE on the freeway, but gut feel says it's less stress on the car being able to cruise on the freeway in a single gear than taking the surface route with the more frequent full stops and the associated gear shifts...

Steady state driving will of course put less stress on fewer components than city driving, which is the worst place for a vehicle to spend it's time. How many times in an ad have I seen a vehicle with hig mileage advertised as having mainly highway miles, and after seeing the vehicle realizing the thing still looks new? Yet a vehicle used for pizza delivery or taxi service seems to suffer more despite having fewer miles?

There should be a hour meter installed as standard on a vehicle, because the hours spent with the engine running compared to the miles driven will tell a much more detailed story than miles alone.

Our Maxima has 210K+ miles on it, but for most of its existance it was driven a 20 mile route between towns. 17 miles of this route is a 55 mph 2 lane road that, while curvy, is basically a constant speed type of road. It was also driven by a lady who valued her car. This car feels new, despite having no suspension work done in years.

I drove another Maxima of the same year that I think had been driven hard and fast by a youngster. (You can generally tell if you look close enough.) It felt wayward and unruly, despite having nearly half the miles.

In my years of driving I've owned close to 20 vehicles, and I can say with certainty that the driving done with a vehicle does a number on the various components thereof according to the type of driving. 200k miles on highways is nothing on a good quality vehicle compared to 100k miles in a congested city.