How come small cars 10-12 years ago have better mpg ratings than newer small cars? (traction control, fuel)

[ColdCanadian]

I was looking on the net at new small cars like Cobalt, Focus etc. and comparing them to older small cars from 1995 and 1996 like the Escort, Cavalier, Neon etc. in an old Motor Trend magazine.

The numbers were confusing.

Take the base model Dodge Neon for example:
In 1995 it was rated at 29 city and 38 highway.
In 1998 it was rated at 26 city and 35 highway.
In 2000 it was rated at 24 city and (I think) 31 highway.
In 2002 it was rated at 22 city and 31 highway.

The newer Neon weighs 100 lbs more but this can't be the reason.
All the specs I looked at had the 2.0L inline 4 cyl.
The hp and torque numbers are the same, or only slightly lower on the newer models.

*Have there been any changes to how cars have their economy rated?
** Has OBD II, dual-cats or newer pollution controls sucked out more fuel economy.

I'm really confused.

[Nepenthe]

There were changes to how the EPA arrives at "official" figures, but they didn't take effect until 2007 I believe. I'm not aware of any changes prior to that -- in fact, many felt the old standards were pretty outdated so my impression is they were pretty antiquated by 2006. Subjectively, I would say it's not possible to get the same mileage with an identical vehicle just because there are SO MANY FREAKIN CARS on the road and so many more streetlights. But I don't think this was accounted for by the EPA.

WEIGHT is probably going to be the primary culprit in many cases. Cars keep creeping up in weight. Every generation of a long-running vehicle is larger (Camry, Accord, Corolla, Civic, Maxima, Sentra, Altima, etc.). Feature content, safety constructs, and creature comforts keep increasing in complexity and number. It's a bit of an arms race.

With weight comes the need for more displacement and/or a slightly higher state of tune. Wheels and tires become wider and larger in diameter, increasing parasitic losses. New emissions requirements mandate more restrictive exhaust collectors and catalytic converter systems. Aerodynamics have improved, but that improvement is tempered by enlarged frontal profiles.

I don't have a reference, but I believe the 15% Ethanol gasoline used most places today gives less power and less fuel efficiency by volume of fuel than previous fuel. Oxygenation also robs some power.

I'm not sure this explains those Neon figures, but these are pretty good rules of thumb. Weight and the obsession with "safety" (of the passive variety) and gigantism in car design are the main issues that have dragged down vehicle fuel economy.

[ColdCanadian]

Originally Posted by Nepenthe

There were changes to how the EPA arrives at "official" figures, but they didn't take effect until 2007 I believe. I'm not aware of any changes prior to that -- in fact, many felt the old standards were pretty outdated so my impression is they were pretty antiquated by 2006. Subjectively, I would say it's not possible to get the same mileage with an identical vehicle just because there are SO MANY FREAKIN CARS on the road and so many more streetlights. But I don't think this was accounted for by the EPA.

WEIGHT is probably going to be the primary culprit in many cases. Cars keep creeping up in weight. Every generation of a long-running vehicle is larger (Camry, Accord, Corolla, Civic, Maxima, Sentra, Altima, etc.). Feature content, safety constructs, and creature comforts keep increasing in complexity and number. It's a bit of an arms race.

With weight comes the need for more displacement and/or a slightly higher state of tune. Wheels and tires become wider and larger in diameter, increasing parasitic losses. New emissions requirements mandate more restrictive exhaust collectors and catalytic converter systems. Aerodynamics have improved, but that improvement is tempered by enlarged frontal profiles.

I don't have a reference, but I believe the 15% Ethanol gasoline used most places today gives less power and less fuel efficiency by volume of fuel than previous fuel. Oxygenation also robs some power.

I'm not sure this explains those Neon figures, but these are pretty good rules of thumb. Weight and the obsession with "safety" (of the passive variety) and gigantism in car design are the main issues that have dragged down vehicle fuel economy.

Interesting...

But most of the smaller cars I looked at only increased their weight by 100 lbs, which is less than 5% increase in weight and yet have mpg ratings more than 10% lower than they used to be. These same cars that I researched are just as long, wide and tall as their predecesors!

I'm not a huge fan of wider tires on ordinary vehicles (sports cars, hot rods etc. fine) and I HATE larger diameter wheels with lower profile rubber when they're not on sports cars for three reasons; they absorb less shocks and jolts, (I like the floaty ride of older tires) lower profile tires cost exponentially-more each 1" 'plus-size' for the same overall wheel and tire size (less material to make the tires, wtf!?!) and that it increases the weight of the overall wheel and tire combination, which obviously robs accelerating power and braking performance.

However my preference for older-style wheels and tires does not make it available on newer vehicles.

*Buying a vehicle 15-25 years old would not be a nice way around that, since I live in the "rust belt."
Cars rust really fast up here, which is why I'm trying to find out which newer vehicles would annoy me the least.

[Stratford, Ct. Resident]

Axle/Final Drive Ratio.

Changes in the gear ratio can dramatically affect mpg numbers. Maybe that Neon you referenced lost mpg because Chrysler went to a more aggresive gear. It's a cheap fix for improving performance, but it causes the engine to run at a higher rpm, hence the fuel economy reduction.

[Chris M]

Originally Posted by ColdCanadian

Interesting...

But most of the smaller cars I looked at only increased their weight by 100 lbs, which is less than 5% increase in weight and yet have mpg ratings more than 10% lower than they used to be. These same cars that I researched are just as long, wide and tall as their predecesors!

I'm not a huge fan of wider tires on ordinary vehicles (sports cars, hot rods etc. fine) and I HATE larger diameter wheels with lower profile rubber when they're not on sports cars for three reasons; they absorb less shocks and jolts, (I like the floaty ride of older tires) lower profile tires cost exponentially-more each 1" 'plus-size' for the same overall wheel and tire size (less material to make the tires, wtf!?!) and that it increases the weight of the overall wheel and tire combination, which obviously robs accelerating power and braking performance.

However my preference for older-style wheels and tires does not make it available on newer vehicles.

*Buying a vehicle 15-25 years old would not be a nice way around that, since I live in the "rust belt."
Cars rust really fast up here, which is why I'm trying to find out which newer vehicles would annoy me the least.

There are good, low-mile cars to be found on ebay. You might have to pay $500+ to have them shipped to you, but for a couple thousand, you can get a really nice older vehicle.

People may turn their nose at an older car, but no one realizes that my car is twenty years old, because it was well maintained.

[studedude]

10 years ago people bought small cars as a second car and were only interested in fuel mileage. A majority of them were little more than a box with a small engine. There was little or no concern with performance or creature comforts. People are now buying small cars as their primary vehicle and expect a lot more from them. Very few 1996 small cars included, power steering, cruise control, ABS, leather, heated seats, traction control, nav system, a 270HP 3.5 ltr engine and a host of other things we "think" we need. You see on this thread people touting some 1930 or 40 something that got 40MPG. What they don't tell you is that you could time a vehicle in that era, that got that kind of mileage, 0-60 performance with a sun dial. I don't how things are where you live but in todays traffic if you cannot reach highway speed in a reasonable amount of time you become a hazard.

[ESFP]

I've always wondered why new small cars brag about mileage with zero comfort. My first car was a 1966 VW Karman Ghia that got 35 mpg. My wife now drives a 2006 Acura that gets 29 mpg. A 5-mpg increase isn't worth the puny no-frills cars today.

[Drover]

It also bears mentioning that there were various configurations of the Neon driveline setup, including 3-speed automatic versus 4-speed automatic versus 5-speed manual; the SOHC 130HP engine versus the DOHC 150HP engine and eventually the 230HP SRT-4; and shorter gearing for "sportier" models, especially the Neon ACR which was for all intents and purposes a factory-tuned autocross car. (My brother had an ACR -- it was geared so low that it absolutely buzzed on the highway, turning about 3500 RPM.) Make sure you're comparing apples to apples from each year to the next where driveline configuration is concerned.

[PNW-type-gal]

According to the EPA's website:

1996 Neon 24 35 (Manual, 5 spd, 2L)
1998 Neon 25 37 (Manual, 5 spd, 2L)
2000 Neon 24 31 (Manual, 5 spd, 2L)
2002 Neon 24 31 (Manual, 5 spd, 2L)
2004 Neon 25 32 (Manual, 5 spd, 2L)

It looks like they are comparing similar base-trim models.

Fuel Economy

[sunsprit]

The two big differences:

1) The older high mpg cars were pretty stripped compared to today's models. All of the added accessory/comfort/convenience items take energy to power them which comes from the alternator driven by the motor. I like my old BMW 1600's and 2002's as drivers, but they're pretty stark cars compared to the 4 cylinder models that followed them equipped with A/C, cruise, more heater airflow, stereo systems (even the radio/speakers in a 2002 was a dealer installed option), more powerful lighting, electric seats/mirrors, and so forth. The old cars had 35-45 amp alternators, the new ones have at least double that capacity.

2) Looking closely at the cars of 10-15 years ago, the technology of emissions controlled horsepower per cubic inch was still very much in an early development stage. If you check out the specific fuel consumption numbers (lbs of fuel per horsepower hour), you'll see that the newer cars use less fuel per hp/hour with cleaner exhaust emissions. However, with the improved performance heavier cars with more options, that hp is used to power much more ... and the overall balance of mpg drops because the car is doing so much more. If you'd take the later engine and place it in an appropriately geared older model without all the stuff in it, you'd get better fuel economy and/or performance in that car.

Major engine developments included variable cam timing, better cam profiles, better designed intake/exhaust tracts, better computer modeling of the ignition profiles, better fuel injection delivery, better combustion chamber shapes, multiple valves in the heads, better oxygen sensing/feedback loops, and better use of mid-range torque curves via gearing (and more gears, in some cases).

I think the manufacturer's have called it right ... they're delivering improved safer transportation and better fuel economy. Few of us would go back to 40HP VW's or R-10 Renault's, or MG Midgets/AH Sprites/TriSpitfires as daily transportation cars ....