> You drive the rear wheel drive V8 that weighs 2x my car's weight
Actually, a lot of newer cars weigh more, not the other way around. I believe that this is mostly due to additional safety devices. For example a 1967 Mustang weighs 2500-3000 lbs[1], while a 2014 Mustang is 3500-3700 lbs[2]. A 2014 Toyota Prius is 3000 lbs[3], while a 2014 Corolla weights 2800 lbs[4]. A 1980 Corolla weighed 2000 lbs[5]. As you see, that rear wheel drive V8 weighs the same as the Prius. I think the improvements in MPG mostly come from improvements in engine efficiencies, not weight savings. I don't know what kind of car you drive, but I'd be surprised if it only weighs 1500 lbs.
That being said, I mostly agree with your other points.
Well, yes, cars are heavier thanks to life saving crumple zones and other safety engineering. I'd rather crash in a prius than a classic mustang.
That said, its also a little unfair to compare a 4 door sedan to a 2 door sports car. Modern cars are still heavier, but the difference is a bit more sane.
I think my dad's Cadillac when I was growing up was over 5,000 lbs. The 70s and 80s certainly had heavy cars, but heavy and death-traps and super shitty mpg.
My car (Kia Soul) weighs 2700lb and is considered light. Indeed the newer models have been steadily increasing in weight as more and more features are added. Of course part of this is the consumers fault, more features means more parts which means more weight! The 2012 version of the Soul is currently up to nearly 3000lb!
Actually, a lot of newer cars weigh more, not the other way around. I believe that this is mostly due to additional safety devices. For example a 1967 Mustang weighs 2500-3000 lbs[1], while a 2014 Mustang is 3500-3700 lbs[2]. A 2014 Toyota Prius is 3000 lbs[3], while a 2014 Corolla weights 2800 lbs[4]. A 1980 Corolla weighed 2000 lbs[5]. As you see, that rear wheel drive V8 weighs the same as the Prius. I think the improvements in MPG mostly come from improvements in engine efficiencies, not weight savings. I don't know what kind of car you drive, but I'd be surprised if it only weighs 1500 lbs.
That being said, I mostly agree with your other points.
[1] http://auto.howstuffworks.com/1967-1968-ford-mustang-specifi...
[2] http://www.motortrend.com/cars/2014/ford/mustang/specificati...
[3] http://www.toyota.com/prius/features.html#!/weights_capaciti...
[4] http://www.toyota.com/corolla/features.html#!/weights_capaci...
[5] http://www.ultimatespecs.com/car-specs/Toyota/5260/Toyota-Co...