Why isn't the fuel economy better?

[Dadhawk]

Originally Posted by Tcoat

If you broadened that Y axis a bit it would be a flat line.

Yep...

[Dadhawk]

If you want to "ride the wave" here is how it looks over the entire period, by month. Note the overall trend line shows it has increased over time even though my driving habits have stayed pretty much the same.

[Ultramaroon]

Originally Posted by Tcoat

That is probably exactly what mine would look like if I were not far too lazy to track it that closely. If you broadened that Y axis a bit it would be a flat line.

Originally Posted by Dadhawk

Yep...

Even flatter if you plotted it logarithmically.

Don't winter blends have a slightly lower energy density?

I attribute the slight increase to driveline break-in. Just a thought but it is interesting.

[Tcoat]

Originally Posted by Ultramaroon

Even flatter if you plotted it logarithmically.

Don't winter blends have a slightly lower energy density?

I attribute the slight increase to driveline break-in. Just a thought but it is interesting.

Yes winter blends do as well as anti freeze elements in case you get some water. I concur with the driveline break in theory. If you keep the car long enough it should peak and then start to taper down at roughly the same rate as the break in changes to wear out. If Hawk keeps the data rolling and doesn't change driving habits we may actually start to see the decline in a couple of years or so. I have seen loads of break in and wear out data on car components before (most artificially induced on test rigs) but this is the first time I have seen reliable data and results on a whole car. This is way to study things not the "I can't wait to see sombody drive both and tell me which is better" crap going on in some threads.

[Impureclient]

I don't know, Tcoat. From the looks of that graph, in 5 more years he'll be getting 36 mpg. In 2031 he'll be getting close to 40 mpg.
If it keeps it up it can eventually outpace electric cars for efficiency and we can go back to only using fossil fuels and give up on the electric movement.

[Tcoat]

Originally Posted by Impureclient

I don't know, Tcoat. From the looks of that graph, in 5 more years he'll be getting 36 mpg. In 2031 he'll be getting close to 40 mpg.
If it keeps it up it can eventually outpace electric cars for efficiency and we can go back to only using fossil fuels and give up on the electric movement.

LOL wouldn't that be cool. Miss the "peak and then decline" part?

[Impureclient]

The problem is the peak on the "peak and decline" theory on my graph will be somewhere in 20 years if I keep only putting 4k miles a year on it.

[notout86]

Originally Posted by Tcoat

Having it heat up 2 minutes faster is not going to give you any perceivable mileage increase.

You need to consider the proportion of driving before it is warmed up to the total trip. e.g. if you start up cold in the morning and drive 7 minutes to work then start up cold to drive home then for half the time you are driving rich. Do that 5 days a week, 52 weeks a year and measure the consumption. Then go for a 50km spin at the weekend and measure and compare that consumption.
I have noticed the effect with a change of job location from close to home then further away.

[strat61caster]

Originally Posted by notout86

You need to consider the proportion of driving before it is warmed up to the total trip. e.g. if you start up cold in the morning and drive 7 minutes to work then start up cold to drive home then for half the time you are driving rich. Do that 5 days a week, 52 weeks a year and measure the consumption. Then go for a 50km spin at the weekend and measure and compare that consumption.
I have noticed the effect with a change of job location from close to home then further away.

I did the opposite, shortened my commute from an hour to 15 minutes, my fuel mileage went from 27-29 to ~24 but I use half as much gas in a month so it was totally worth it on the fuel cost front.

[humfrz]

Originally Posted by notout86

These cars get up to operating temperature fairly slowly. I doubt that the fuel figures published take this into account. I'm looking for a way to get it to warm up more rapidly and thus reduce fuel consumption, without any downside. Any ideas?

Bubba says to put a blanket over the hood and a 100W lightbulb in the engine compartment ......


humfrz

[why?]

Originally Posted by Dadhawk

If you want to "ride the wave" here is how it looks over the entire period, by month. Note the overall trend line shows it has increased over time even though my driving habits have stayed pretty much the same.

that's about what mine looks like too. Interesting. I wonder how much lighter I'd have to go to see it move upwards. Probably not worth the money. I'll probably do it anyways at some point.

[humfrz]

Originally Posted by venturaII

I've found this car to be one of the quickest warming vehicles I've ever owned.

Were all your previous vehicles diesel powered ..... ??




humfrz

[humfrz]

Originally Posted by mazeroni

I am also super impressed with the AC so long as you are moving. I find that when at a stop the air blowing out the vents gets a good deal warmer (talking 100 F ambient temps). I am sure there is a good explanation. Also the super small interior makes it easy to modulate. My GTI was a bit of a pain. Go around a corner and the air in the hatch would move to the front.

Though my fuel economy tanks when running the AC. I don't know whether i trust the instant MPG gauge, but the different between AC on and off is at least 6 mpg. I have no statistical evidence, but I feel like I started to use at least 25% less fuel when the temps dropped to 70 around here and I keep the windows down.

I reckon your instant MPG gauge is ah messen wich you ...... if it shows you 6 MPG between the A/C being on of off .....


humfrz

[Tcoat]

Originally Posted by notout86

You need to consider the proportion of driving before it is warmed up to the total trip. e.g. if you start up cold in the morning and drive 7 minutes to work then start up cold to drive home then for half the time you are driving rich. Do that 5 days a week, 52 weeks a year and measure the consumption. Then go for a 50km spin at the weekend and measure and compare that consumption.
I have noticed the effect with a change of job location from close to home then further away.

Still so minuscule a difference to be even measured. If you are driving 7 minutes to work your fuel usage is so small that gaining an extra hundredth of a mile per gallon for three minutes with a warmer engine means you may save $10 over the life of the car. This is the sort of silly shit they talk about over on Prius Chat.