10 lightest new cars available in 2010 (North America), 2009 (Europe)

[ShadeTreeMech]

Originally Posted by Frank Lee

You shut off half the cylinders and that improved fe?

A simplistic statement for a slightly more complex procedure. I put in a switch that disconnected the ground to half the injectors, which I would activate when low power was needed, even at idle. It would be gutless, but had the power to move the truck and could even maintain cruise on a flat road. Problem was, the o2 sensor read a "lean" condition and the injectors on the running side were pumping in way too much fuel, causing excess fuel to wash into the oil pan--bad news. So I disconnected it.

If I were to reroute the exhaust piping so only one side was read by the o2 sensor it might actually work as desired. If I also separated the intake and had the comp only read one side of the engine I'm sure it would work. Even considering the extra fuel being dumped into the running side I used less fuel per tank. I got an extra 2-3 mpg regularly (I was getting an average of 15) and one tank of nearly 20 mpg.

[TheEnemy]

Originally Posted by JacobAziza

Plus, mass tends to cause the impact: 1/2 the weight = 1/2 the braking distance = no impact. No impact > "winning" impact

The weight/stoping distance thing is way more complicated than that.

Yes typically the heavier the vehicle the longer it takes to stop, but it is also very dependant on the brakes, suspension, and tires. My pickup is the lightest car we own, it also has the longest stoping distance despite having good tires on it. My wifes 05 Accord can't quite out stop my Jeep despite having a supierior braking system and suspension. And thats with the rear brakes on the Jeep still not working 100%.

Yes, if the lady had a smaller car she might have fit without causing a wreck, but my argument isn't that larger cars are or aren't safer. My statement was concerning Frank's belief that he is a good enough driver to avoid anything, even a distracted driver that isn't paying attention to what they are doing. I used to believe the same way until the realities caught up with me.

The whole roll over thing is in most cases overstated. Yes there were a few models built that were less stable than my 25 year old Jeep, and it didn't help that the cheap tires they put on them were prone to failure, even when properly inflated. I have yet to roll either my pickup or my Jeep (just a matter of time), and I have done some rather interesting things with both.

[ShadeTreeMech]

I suppose there are 3 schools of thought. Make a vehicle light enough to avoid an accident, make it strong enough to "win" the accident, or build it assuming it will be involved in a bad accident and the passengers must survive.

I propose filling all cars with a lightweight metallic foam or metallic bubblewrap, and have carbon dioxide be the gas contained therein, or some other fire retardant chemical that is lightweight. The crumple zones would have to be engineered for a crash at survivable at much higher speeds than are currently enforced. And research into making carbon fiber much cheaper would be a gov't mandate, to the end that all cars would use it to make the vehicles lighter. Yes, a light car is better, but it should also make sure the passengers will survive a horrific accident.

[Frank Lee]

Originally Posted by ShadeTreeMech

A simplistic statement for a slightly more complex procedure. I put in a switch that disconnected the ground to half the injectors, which I would activate when low power was needed, even at idle. It would be gutless, but had the power to move the truck and could even maintain cruise on a flat road. Problem was, the o2 sensor read a "lean" condition and the injectors on the running side were pumping in way too much fuel, causing excess fuel to wash into the oil pan--bad news. So I disconnected it.

If I were to reroute the exhaust piping so only one side was read by the o2 sensor it might actually work as desired. If I also separated the intake and had the comp only read one side of the engine I'm sure it would work. Even considering the extra fuel being dumped into the running side I used less fuel per tank. I got an extra 2-3 mpg regularly (I was getting an average of 15) and one tank of nearly 20 mpg.

It's a proven fail.

[TheEnemy]

Originally Posted by ShadeTreeMech

I suppose there are 3 schools of thought. Make a vehicle light enough to avoid an accident, make it strong enough to "win" the accident, or build it assuming it will be involved in a bad accident and the passengers must survive.

I propose filling all cars with a lightweight metallic foam or metallic bubblewrap, and have carbon dioxide be the gas contained therein, or some other fire retardant chemical that is lightweight. The crumple zones would have to be engineered for a crash at survivable at much higher speeds than are currently enforced. And research into making carbon fiber much cheaper would be a gov't mandate, to the end that all cars would use it to make the vehicles lighter. Yes, a light car is better, but it should also make sure the passengers will survive a horrific accident.

I think your taking it too far, (I'm guessing your being sarcastic though)

All things considered building cars is an exercise in compromise. Small and light in many ways improves safety, it makes it easier to make it have good performance and agility. Larger and heavier while not as able to avoid an accident has more room to crumple while still keeping its occupants safe. Heavy unyeilding tanks are a loose loose type of construction, they don't crumple, so if they hit something of equal or greater mass the occupants feel the full instatainious impact, and if what they hit is smaller, that one looses.

Building cars is an exercise in compromise, keep it light pushes toward smaller cars with thinner materials, while safety pushes for larger thicker materials. More modern materials can make the same safety but at a higher cost.

All that and Automobile manufacturers still have to keep an eye on what the majority are wanting and willing to pay for that year.

[jamesqf]

Originally Posted by TheEnemy

My statement was concerning Frank's belief that he is a good enough driver to avoid anything,,,

Mine is just the flip side of that: of course you can't aviod EVERYTHING, but you can avoid some things. And it's a fact that the only accidents I've ever been involved in were me getting rear-ended while sitting in a line of stopped traffic, which I think count as unavoidable by any reasonable definition.

The whole roll over thing is in most cases overstated. Yes there were a few models built that were less stable than my 25 year old Jeep, and it didn't help that the cheap tires they put on them were prone to failure, even when properly inflated. I have yet to roll either my pickup or my Jeep (just a matter of time), and I have done some rather interesting things with both.

Not overstated: if anything, the risk of rollover is understated. Take those cheap tires: I've had several high-speed blowouts in sports/muscle cars, which were perfectly controllable, just noise, vibration, and a bit of drag. It's not particular models, either, but just simple physics: give something a higher center of gravity, and it rolls easier.

[TheEnemy]

I have also had several high speed blow outs, on my pickup, one of which the only indication was the noise of it going. Yes a vehicle with a higher center of mass is going to have a greater chance of rolling, but all the hype I hear makes it seem as though any SUV is going to roll over if the driver so much as sneezes.

Metro: can you give some examples of how to avoid being rear ended, especially at a light?

[AJI]

I'd suggest that one way of avoiding being rear-ended is brake in plenty of time for lights to make sure the car behind you has chance to do the same.

Another suggestion is to keep your foot on the brake pedal at a stand still until you're sure the car behind has enough space to stop (for greater visibility obviously)... and keep the car in gear and leave a gap to the car in front, so if the car behind has left it too late, you still have a couple of meters to move forward to give yourself space to avoid an accident.

Pretty much all driving is about planning ahead, and that doesn't necessarily mean that your planning has to be whilst on the move - often planning in traffic can be equally useful.

[ShadeTreeMech]

I can recall 2 instances of my parents getting rear ended, or nearly so in one of them.

The first one, my mom was at a downhill stop light in Colorado during a snowy day, and saw in the rearview a car coming in too fast. She knew being rear ended was unavoidable so she moved as close to the vehicle in front as she dared to minimize damage; it worked, the car barely had a scratch on the front and the car in front of her was nearly unscathed.

Another time, my dad came to a stoplight on a highway with a 55 mph speed limit. He stopped, and in the rear view saw a semi barreling in way too fast, so he cursed a bit and pulled off into the turn lane. The semi's front bumper stopped a few feet in front of our front bumper, good thing he was in the other lane.

Both times disaster was averted by paying attention to surroundings. In the second story, I'd have likely been killed had my dad not reacted as he did. But having a margin for error in the worst case scenario is always preferrable.

[rmay635703]

Originally Posted by ShadeTreeMech

A simplistic statement for a slightly more complex procedure. I put in a switch that disconnected the ground to half the injectors, which I would activate when low power was needed, even at idle. It would be gutless, but had the power to move the truck and could even maintain cruise on a flat road. Problem was, the o2 sensor read a "lean" condition and the injectors on the running side were pumping in way too much fuel, causing excess fuel to wash into the oil pan--bad news. So I disconnected it.

Many cars have 2 O2 sensors, maybe spoofing one and using the other would work? Or maybe reading how much the O2 was off voltage wise and correcting it a bit