You may think that upgrading your 25mpg sedan to a 50mpg hybrid will save the world, but it is far better to get those 10mpg trucks into 20mpg trucks. How is that so? I'm getting 25mpg more with the hybrid, vs only 10mpg more. Do the real math...watch below:
This is what happens when management professors try to teach math. I'll respond with a longer comment later, but the conclusion will basically be this: MPG is a linear equation by mathematical definition and price directly correlates to MPG for cost effectiveness (There's nothing exponential about it). Basically: Their math is right, but their conclusions are wrong.
GJ said about 4 hours later
Agreed, and I'll expand a bit. They don't have a proper thesis, nor statement of problem. What exactly are they trying to address? Because they lack that, it's easy for them to come up with a solution--for it doesn't need to fix a problem they didn't state.
In fact, after watching it, I'm not really sure what their point was. Even as some kind of propaganda piece, it fails horribly.
Geoff said about 5 hours later
OK guys...everyone is on a hybrid craze right? I would say the average american has 2 cars...and usually, I see a sedan and a truck/suv. So, somebody wants to save more gas, so they upgrade their sedan to a hybrid because everyone and their mother is telling them Hybrid is the way to go. A better decision would be to upgrade their SUV/truck to a more efficient SUV/truck. Some would think upgrading their 25mpg sedan to a 45mpg hybrid will save more gas money than upgrading their 12mpg truck to an 18mpg truck, but assuming the right conditions are met (aka, you drive equal amount of miles on both cars, same kind of road conditions/highway/city, etc...), upgrading the SUV or truck to another SUV or truck with slightly better MPGs could actually save them MORE money and use LESS gas, than upgrading their sedan to a hybrid.
I'm not saying hybrids are a dumb buy. For me, I thought dropping my mpg from 17 to 15 wasn't a huge deal. It's only 2mpg (I was thinking about turning off 4 cyl Active Fuel Management). However, 2mpg on my car actually means more than I originally thought. This is just a different way of viewing MPG. And I'm not the only one...at least not the G8 owners. They all say the same thing. I'll disable AFM, I'm only losing 2mpg. Not a big deal. It probably is bigger than they think if they looked at it this way.
Marc said about 5 hours later
Geoff, you're situation is painting a different picture than what this video seems to be trying to market. In your situation, of course you would improve the mileage a little bit on your truck to see more money back in your wallet (That's because you're spending a whole lot more on gas to begin with compared to a 25MPG or 50MPG car).
This video seemingly painted a picture that you're doing a whole lot more by improving your truck a little vs. improving your sedan a lot. It's just not true, it's a matter of perspective. If I double the MPG on my truck and sedan, sure I'm going to see more net money saved on the whole from the truck, but the ratio is still the same and my sedan is still saving me boatloads more than your truck. (I know you agree with this, the video just did a poor job of trying to compare)
This video would have been much better if they did an explanation of why these new hybrid trucks and SUVs are well worth the small increase in MPG. People don't realize that every little bit counts when your gas mileage sucks. When you get closer and closer to the magical number of MPGs where the changes in costs are minuscule to the average income, it doesn't seem like a big deal. But anyway you look at it, if I can lower the amount I'm spending on gas, that sounds pretty dang good and the only way to do that is to increase my MPGs proportionally.
To be honest, people would be better off doing the conversions themselves when buying a new vehicle to see the cost of gas in a money per mile ratio. They would be able to see that at low MPGs, a small increase could save them a lot on gas, but dang that sedan hybrid saves me thousands...maybe I don't need the SUV? Money/mile is a good measurement of what a vehicle is going to cost you in the long run.
Geoff said 1 day later
Right...that was just my thinking. Just never really looked at 2mpg as a big jump. But it is if you've got an inefficient vehicle. It's the same reason why people price things like $299. It looks a lot better than $300....even if it is only $1 difference. :)
Steve said 5 days later
These guys are geniuses! Oh wait. The Europeans have been using liters of fuel/100 kms driven as their fuel economy specification for as long as I've been in the auto industry.
I agree that publishing gallons of gas used per 100 or 1000 miles driven is a good way to express fuel economy. But the government's bigger issue right now is figuring out how to compare energy used per xx miles. That way Chevy doesn't get to claim 240 mpg for the Volt, nor Nissan 300 mpg for the leaf.
GJ said 6 days later
Oh, I dunno, how about kilojoules per mile. Nice agnostic term, nobody needs to worry whether it's gas powered, electric powered, etc.
Oh, wait--then you'd have to figure in how much energy was used to make the gas, or the electricity....oh, never mind.
Steve said 6 days later
Yea, there is no clean way that anyone has figured out to fairly rate how much energy is used to power a car (not just the electricity to charge the car's batteries or the fuel to run the engine, but the cost to generate and distribute the energy).
It will be very interesting to see what the government does to rate the "fuel economy" of the soon to arrive plug in hybrids. From what I've heard, they just "negotiated" a value with Chevy for the Volt, and while they may have used some science to come up with a "negotiated" value, the idea that it's "negotiated" means that it's not a known calculation.
Perhaps a better way to do "energy economy" is calculate a highway energy economy for a full tank of fuel (~40 miles of full electric power than gas power to supplement it), and city fuel economy for whatever the average person's driving distance is for commuting to work AND back (say 50 miles round trip). Then they'd have to put a big caveat on the fact that the city energy economy rating is based on a short trip, and that longer city driving will degrade the energy economy, as you'll be running on gasoline longer.
Geoff said 6 days later
I didn't realize GM was still moving forward with the Volt. It's been awfully quiet for the past year.
GJ said 6 days later
The problem, which of course I've been yapping about since the Volt was announced, was that battery power is hinky at low temps. Any "energy economy" rating you slap on a battery-powered car has to deal with the fact that chemical batteries perform quite differently at different temperatures. Gas engines do too--but they warm up. I half wonder if Chevy and Nissan (and Toyota, for that matter) heat their batteries artificially once the car is running to up the battery efficiency when it's cold--which of course, may or may not make sense, depending on the battery power drop and cost to provide the heating in the first place.
GJ said 6 days later
And yes, the Volt is here and will be released shortly. Jury's out on real-world usage, but I'm curious to see how it pans out. The price tag alone is probably enough to doom it.
Steve said 7 days later
Price tag isn't too bad. $41,000. A lot for a midsize sedan though. Lease rate is reasonable though - $350 a month. Don't forget you get a $7500 tax rebate from the federal gov't if you buy one.
compared to, oh, say, an un-named toyota, yea, it's still pricey. :) not that gm's in position to run it as a loss-leader to build market share, as was done with that fairly well selling hybrid.
Steve said 7 days later
I just wish there were some way to determine actual real world fuel economy of normal drivers. I'm not a fan of the black boxes that the government wants to install in cars, but if they did, they could use those to determine actual real world fuel economy for cars. Oh, and don't believe the fuel economy that your car calculates for you (on many new cars they do that for you) - I've seen cars give readings 2-3 mpg higher than if you actually calculate the fuel economy yourself.
GJ said 8 days later
Mine is just like that--right now it's saying 22 mpg, the reality is at best 20. The van is about 1.5mpg above what we really get. I strongly suggest you keep a record of your gas mileage anyhow--it's a good tool for detecting a problem, as it shouldn't drop out of the blue unless of course the season has changed and you're now driving in the winter. :)
