[NFS]

Originally Posted by bimmerFUD

But with taller gearing, coupled with a decrease in the drag *coefficient* (the factor in front of v * v), it is feasible to make 155mph as fuel efficient as 80mph. Even without the gearing change, you just need a decrease in drag coefficient (and/or cross-sectional area) of 1/4. Not easy, but I can give examples if you're not already bored out of your mind with my diatribe

I'm not bored and I have learned something which is always good. I understand your point about the mathmatical meaning of exponential growth and accept it. However, I don't think it would matter to most people.

But this started off with a much more simple point.

If you take a particular car (say a 330i) then it will return better mpg at 80mph than at 155mph.

Someone suggested that this could be corrected by altering the gearing. This is possibly true but it will not solve the problem entirely because (as you say) if you double the speed you get 4 times the air resistance.

So I accept that if you play with the gearing and somehow find a way to reduce the drag co-efficient of a vehicle in motion you could make a car which could return the same MPG at 155mph as at 80mph.

But the point is that this is not how cars are made. Which is why people will come up with stupid ideas like speed limits on the autobahn to reduce CO2e emissions.

The reality is that there are a million other measures which I would be happier to adopt in order to reduce and possibly offset my carbon footprint, that I would take before I decided to do away with my nice fast car.

Cars will always be a target for the more vehement greens though because they are such a visible symbol of fossil fuel use.

Hopefully we will get widespread use of biofuels soon, which will hopefully make our cars even faster. The downside is reduced mpg, but if your fuel is carbon neutral who cares!

[bimmerFUD]

Originally Posted by needforspeed

Cars will always be a target for the more vehement greens though because they are such a visible symbol of fossil fuel use.

I suppose I'm one of these "vehement" greens. Global warming is not just a bunch of greenies crying wolf. Disclaimer: I'm married to a climate scientist, so I get an earful at home

But I also try to be pragmatic. Lowering speed limits will probably decrease fuel consumption a bit, in the short term. But I believe it will also greatly stifle innovation which in the long term, will mean we won't explore alternative fuels as much, increase mileage (at any speed), etc.

Example: The 335 gets respectable mileage. Good mileage AND performance actually should go hand in hand.

Good engineers love a challenge. Their management may not, because they have to pay more development costs. But can you imagine being a BMW engineer whose designs were limited to 55mph? The good ones will find another career.

Thanks for the discussion, needforspeed, and I definitely didn't intend to be insulting.

[Dante]

Originally Posted by Lost Cosmonaut

To the Germans: My understanding from talking to other Germans I know is that those crappy aggressive drivers on the Autobahn who do stupid stuff are generally eastern european drivers and tourists. Is that right? Or is it changing and more Germans are doing it too?

- LC

There are many agressive german drivers ('boyracers', salesmen in their TDI-Passats) and the new breed of fuel saving eco-fetishists who are blocking the left lane. They even try to save electricity through not signalling when changing lanes...

[Lost Cosmonaut]

Originally Posted by Dante

There are many agressive german drivers ('boyracers', salesmen in their TDI-Passats) and the new breed of fuel saving eco-fetishists who are blocking the left lane. They even try to save electricity through not signalling when changing lanes...

Those eco people who block the left lane, sort of like the people here in the US that go slower than the speed limit in the left lane purposefully to block people from going the speed limit or faster? UGH I hate those types.

Speaking of "saving electricity", if you go to China you will see truck drivers without their lights off AT NIGHT. If you ask them why, they will seriously say they are saving energy. But then, most people in China have only been driving for the past 15 years or so AT MOST so, well, you know

We're planning on European Delivery and I'm hoping to do it sometime soon. It's been a few years since I was in Germany so I hope it hasn't gotten worse! I will say one thing, if they put speed limits on the Autobahn I'm gonna make sure to get over there before they go into effect!

- LC

[Dante]

Originally Posted by Lost Cosmonaut

We're planning on European Delivery and I'm hoping to do it sometime soon. It's been a few years since I was in Germany so I hope it hasn't gotten worse! I will say one thing, if they put speed limits on the Autobahn I'm gonna make sure to get over there before they go into effect!

- LC

Oh well, it's not that bad, but traffic is getting denser. The highways in Bavaria around Munich you will travel on, have not too many restrictions apart from rush hours. We get more and more electronic traffic signs which change the limits depending on the traffic situation.

[Hiii]

Originally Posted by Dante

We get more and more electronic traffic signs which change the limits depending on the traffic situation.

Yes, most of the time with completely stupid regulations :mad:

They sign "fog" and therefore speed limit 60 km/h and the sun is shining ...

Or "heavy traffic jam" 80 km/h - and almost no cars in front of you ...


Sometimes you get the impression, people who are operating that, are sleeping, blind or drunk or what ever ...

[ukthunderace]

The worst people I have noticed on the Autobahn, especially this time of year, are the Nederlanders going back to the Netherlands after their ski holiday. The most agressive are the Swiss coming up the A5. The ones I would like to pull over and punch in the face? Germans in econo-boxes pulling into the fast lane without an indicator who go 100kph and hold up traffic and then won't get out of the way.
Is it any wonder some people are agressive on the autobahn when having to deal with people who don't know how to drive?

[NFS]

Originally Posted by bimmerFUD

I suppose I'm one of these "vehement" greens. Global warming is not just a bunch of greenies crying wolf. Disclaimer: I'm married to a climate scientist, so I get an earful at home

But I also try to be pragmatic. Lowering speed limits will probably decrease fuel consumption a bit, in the short term. But I believe it will also greatly stifle innovation which in the long term, will mean we won't explore alternative fuels as much, increase mileage (at any speed), etc.

Example: The 335 gets respectable mileage. Good mileage AND performance actually should go hand in hand.

Good engineers love a challenge. Their management may not, because they have to pay more development costs. But can you imagine being a BMW engineer whose designs were limited to 55mph? The good ones will find another career.

Thanks for the discussion, needforspeed, and I definitely didn't intend to be insulting.

I guess I am one of those 'greens' myself and I have been doing a lot of work lately on sustainability, embodied carbon and C02e emissions.

I'm with you ... global warming is a reality ...

What I think we need is balance and sense in terms of the way in which we address it.

Fast cars are my own guilty pleasure, but just because I have a 3.0l car doesn't mean my carbon footprint needs to be big.

If I used public transport but flew to the USA twice a year my footprint would be larger.

From what I see at work, I would predict that we will all eventually be trading carbon emissions as we trade money today. This is already happening in business in Europe.

But there are clever ways to sort these things out. My money is on Bioethanol and carbon offsetting. I'm pretty sure we will shortly be able to buy zero carbon petrol, because the producers will have offset their emissions (and yours).

[Zwanzigoetzel]

Originally Posted by ukthunderace

The worst people I have noticed on the Autobahn, especially this time of year, are the Nederlanders going back to the Netherlands after their ski holiday. The most agressive are the Swiss coming up the A5. The ones I would like to pull over and punch in the face? Germans in econo-boxes pulling into the fast lane without an indicator who go 100kph and hold up traffic and then won't get out of the way.
Is it any wonder some people are agressive on the autobahn when having to deal with people who don't know how to drive?

I've lived in Germany 25 years, came to the US 10 years ago, and go back approx. once a year. NOTHING has changed, NOTHING. There have ALWAYS been:

- patches of the autobahn with speed limits

- slow ass drivers with their Fiat Punto or VW Polo going 80km/h on the left lane

- tons of constructions sites

-aggressive drivers (mostly BMWs/Mercedes) from all over Europe

- A billion trucks from the EAST that go past THEIR speed limit, pass even though they are not allowed to and block the middle lane, so that slower drivers are forced to the left lane.

- Talks about introducing speed limits

It's also nothing new that:

- Dutch are the worst drivers on the autobahn
- Opa mit Hut second worst
- And US drivers doing ED third worst.....Juuust kidding.....



Soooo, I don't quite understand what the fuss is all about
Nothing has changed, nothing will change...all is good

Zwanzig

[Dante]

Originally Posted by Zwanzigoetzel

It's also nothing new that:

- Dutch are the worst drivers on the autobahn
- Opa mit Hut second worst
- And US drivers doing ED third worst.....Juuust kidding.....

[Hiii]

Originally Posted by Zwanzigoetzel

It's also nothing new that:

- Dutch are the worst drivers on the autobahn
- Opa mit Hut second worst
- And US drivers doing ED third worst.....Juuust kidding.....

And, additionally, VW Passats TDI and some SUVs and VANs which are going on the left lane with 160 km/h and thinking they were already fast ...

[Ferg]

Reiterating a previous comment about traffic, especially with the trucks here in Germany. I HATE!!!!!!!!!!!!!!! when they pull out in front of you only to pass the other truck that is going the same damn speed, LOL! Elephant law is what I believe it is called. Huge violaters of that every time I get speed up. I agree it will be more environmentally friendly to tack on a speed limit, but how many will obey it. I know I don't travel 130km/h in France or Italy. It would take forever to get somewhere.

[06330i]

nooooooooo! this cant happen. i havent been to germany to drive on the autobahn yettt.