Most of it is due to more powerful engines and the extra weight of bigger models. All vehicles seem to get bigger every time they come out with a new generation. Weight could be drastically reduced by using more light weight alloys and composite materials, which would help with fuel economy...
Fuel economy, why has it not improved more?
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Originally Posted By: JohnnyJohnson
Good question why didn't VW build their prototype diesel they built in the 80's that delivered over 200 MPG? I guess it would have never sold.
The oil companies bought it and hid it in a vault.
Good question why didn't VW build their prototype diesel they built in the 80's that delivered over 200 MPG? I guess it would have never sold.
The oil companies bought it and hid it in a vault.
You performing a bad comparison of EPA ratings against what you get under optimal speeds for you vehicle.
Even though a old vehicle can get 19mpg at 55 mph unless you own the new vehicle you don't know it's optimal MPG above the EPA rated figure.
Even though a old vehicle can get 19mpg at 55 mph unless you own the new vehicle you don't know it's optimal MPG above the EPA rated figure.
Our Prizm has the 1ZZ with the 4 speed automatic and 14" alloy wheels. It weighs approximately 2400 pounds. With that all being said, the car will do 0-60 MPH in about 10 seconds. It was rated under the old EPA standards for 28/31/36 MPG (city/combined/highway). In this vehicle we average around 33 MPG with very mixed driving.
A new 18 Corolla has the 2ZR with the CVT and weighs 2870 pounds. It is recorded that under the new EPA testing it will get 28/32/36 (city/combined/highway). This car will do 0-60 in about 9.8 seconds. This car has 8 airbags and is quite a bit larger. I would imagine that this car would get better mileage than our Prizm in the same driving style and routes, but the new EPA testing did lower the estimates to match more of what an "average" driver would return.
The original CRX returned great economy and estimates through the EPA, but with the new standards I'm sure it would be quite lower. However, these cars had good mileage because they weighed less than 2000 pounds in most models.
I think that you are going to start to see cars that are loosing more weight in the near future since we are close to reaching the maximum potential efficiency of gasoline engines.
A new 18 Corolla has the 2ZR with the CVT and weighs 2870 pounds. It is recorded that under the new EPA testing it will get 28/32/36 (city/combined/highway). This car will do 0-60 in about 9.8 seconds. This car has 8 airbags and is quite a bit larger. I would imagine that this car would get better mileage than our Prizm in the same driving style and routes, but the new EPA testing did lower the estimates to match more of what an "average" driver would return.
The original CRX returned great economy and estimates through the EPA, but with the new standards I'm sure it would be quite lower. However, these cars had good mileage because they weighed less than 2000 pounds in most models.
I think that you are going to start to see cars that are loosing more weight in the near future since we are close to reaching the maximum potential efficiency of gasoline engines.
Originally Posted By: madRiver
You performing a bad comparison of EPA ratings against what you get under optimal speeds for you vehicle.
Even though a old vehicle can get 19mpg at 55 mph unless you own the new vehicle you don't know it's optimal MPG above the EPA rated figure.
That is just it, I can, kind of with our 2016 Suburban. Yes it is heavier but the best we have gotten with it is only 21mpg. Our 98 Suburban was getting 19mpg. But for the most part we are only getting 19 with it. Same as what we were getting with our 2011 GMC Acadia. Plus we have a lot of "bragger" in my church with new GM trucks and they are only claiming 20 to 22mpg.
You performing a bad comparison of EPA ratings against what you get under optimal speeds for you vehicle.
Even though a old vehicle can get 19mpg at 55 mph unless you own the new vehicle you don't know it's optimal MPG above the EPA rated figure.
That is just it, I can, kind of with our 2016 Suburban. Yes it is heavier but the best we have gotten with it is only 21mpg. Our 98 Suburban was getting 19mpg. But for the most part we are only getting 19 with it. Same as what we were getting with our 2011 GMC Acadia. Plus we have a lot of "bragger" in my church with new GM trucks and they are only claiming 20 to 22mpg.
Fuel economy is getting a little better, even with cars get so much bigger and heavier. My 89 Civic weighed only 2100 lbs, a new Civic is well over 3000 lbs, basically a 50% increase. Gotta lug around those 14 airbags, heavy automatic climate control systems, ABS systems etc etc etc. But the economy is very similar. If you want much better economy, you need to combine todays tech with no frills. But nobody is willing to buy a car like that, or even allowed to.
Originally Posted By: mightymousetech
Fuel economy is getting a little better, even with cars get so much bigger and heavier. My 89 Civic weighed only 2100 lbs, a new Civic is well over 3000 lbs, basically a 50% increase. Gotta lug around those 14 airbags, heavy automatic climate control systems, ABS systems etc etc etc. But the economy is very similar. If you want much better economy, you need to combine todays tech with no frills. But nobody is willing to buy a car like that, or even allowed to.
Dropping a newer drive-train into an older vehicle would be an interesting experiment. Although with the styling of the 80s you will lose aerodynamics.
My friend had a V8 swapped Ford Ranger for a while, and it got decent mileage because of the power to weight ratio. The truck was a regular cab short bed with 2WD and weighed nothing.
Fuel economy is getting a little better, even with cars get so much bigger and heavier. My 89 Civic weighed only 2100 lbs, a new Civic is well over 3000 lbs, basically a 50% increase. Gotta lug around those 14 airbags, heavy automatic climate control systems, ABS systems etc etc etc. But the economy is very similar. If you want much better economy, you need to combine todays tech with no frills. But nobody is willing to buy a car like that, or even allowed to.
Dropping a newer drive-train into an older vehicle would be an interesting experiment. Although with the styling of the 80s you will lose aerodynamics.
My friend had a V8 swapped Ford Ranger for a while, and it got decent mileage because of the power to weight ratio. The truck was a regular cab short bed with 2WD and weighed nothing.
My father in law regularly topped 50mpg in his old ECOdiesel Jetta, even over 300,000 miles. Slow, sure (like, 60hp), but perfectly fine around town (would pull from 1200rpm in any gear) and happy to run 80mph. His Mirage consistently gets mid-40s, despite his usual 75+MPH highway speeds. It isn't as nice inside as his loaded Jetta (which I think was a Wolfsburg model), but isn't bad.
Originally Posted By: mightymousetech
For best fuel economy you want to accelerate fairly hard and get to a constant speed. It is only while driving a constant speed to you get decent efficiency. I see people who accelerate very slowly, but constantly and never cruise at a steady speed. Those drivers will get terrible economy. But you are doing it right, time your speed so you don't have to slow down and maintain a constant speed. [/quote]
Thats right. Fuel mileage is abysmal while accelerating, typically well under 15MPG in a 4 banger. Accelerate briskly then level off. Barely keep that throttle cracked and should get you over 50MPG at 45-50 mph. If you are driving block to block and stopping there is no hope other than a Hybrid/electric.
For best fuel economy you want to accelerate fairly hard and get to a constant speed. It is only while driving a constant speed to you get decent efficiency. I see people who accelerate very slowly, but constantly and never cruise at a steady speed. Those drivers will get terrible economy. But you are doing it right, time your speed so you don't have to slow down and maintain a constant speed. [/quote]
Thats right. Fuel mileage is abysmal while accelerating, typically well under 15MPG in a 4 banger. Accelerate briskly then level off. Barely keep that throttle cracked and should get you over 50MPG at 45-50 mph. If you are driving block to block and stopping there is no hope other than a Hybrid/electric.
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Originally Posted By: JohnnyJohnson
Good question why didn't VW build their prototype diesel they built in the 80's that delivered over 200 MPG? I guess it would have never sold.
That would be an extraordinary fuel efficient engine. I doubt modern day materials would stand up to that high energy efficiency. Perhaps your dad or more likely your grandpa told you that 100 MPG carburetors were developed six decades or so ago but the oil companies bought up the patents. There is only one way to improve fuel efficiency and that is to use more of the energy at the wheels and reduce(greatly here) heat rejected by the cooling system. Not very likely. My dad liked to tell us about the 100 MPG carburetor.
Good question why didn't VW build their prototype diesel they built in the 80's that delivered over 200 MPG? I guess it would have never sold.
That would be an extraordinary fuel efficient engine. I doubt modern day materials would stand up to that high energy efficiency. Perhaps your dad or more likely your grandpa told you that 100 MPG carburetors were developed six decades or so ago but the oil companies bought up the patents. There is only one way to improve fuel efficiency and that is to use more of the energy at the wheels and reduce(greatly here) heat rejected by the cooling system. Not very likely. My dad liked to tell us about the 100 MPG carburetor.
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Your truck is rated for 16 mpg on the highway while the new ones are rated for 22 mpg highway. That's a 37.5% increase in fuel economy. Your truck has 285hp and he new ones have 355hp, a 24.5% increase. I say all of that is impressive. The new 4.3L has as much horsepower as your 5.3L.
Originally Posted By: SonofJoe
Man, machine & engine oil in perfect harmony!
The BITOG mission statement right there!
Man, machine & engine oil in perfect harmony!
The BITOG mission statement right there!
I see people all the time driving faster than what they need to. All it does is get them to the red light sooner which makes them wait longer for the light to turn green. Hurry up and wait mentality.
The number one reason fuel economy numbers haven't improved, is the emissions controls on these engines requires them to burn more fuel to run within the parameters of the system, as a whole.
This is true for gasoline engines, but EXTREMELY true of anything diesel.
I think the other things is increased weight - from accessories, as well as "crumple zones" and side-crash strength bars.
This is true for gasoline engines, but EXTREMELY true of anything diesel.
I think the other things is increased weight - from accessories, as well as "crumple zones" and side-crash strength bars.
NOBODY drives 55 mph anymore!
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I would think with all the cheap plastic everywhere and lack of metal,cars would be lighter.
Originally Posted By: aquariuscsm
I would think with all the cheap plastic everywhere and lack of metal,cars would be lighter.
But they're heavier: more structure to meet front and side impact standards, more standard features like power windows and power seats that have heavy electric motors, and all the other features that are now standard, like ABS, airbags, everything adds weight and the same model cars (e.g. Civic or Corolla) have far more interior room than they did before. So, they're bigger, which makes them heavier...
I would think with all the cheap plastic everywhere and lack of metal,cars would be lighter.
But they're heavier: more structure to meet front and side impact standards, more standard features like power windows and power seats that have heavy electric motors, and all the other features that are now standard, like ABS, airbags, everything adds weight and the same model cars (e.g. Civic or Corolla) have far more interior room than they did before. So, they're bigger, which makes them heavier...
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