Gas Milage

[Guest tony78_280z]

In Duscussion of AAA vs EPA and car manufactureers posted gas milage.

"It's not accurate on the highway speeds' date='" says one.

 

"I'm sure they take it downhill with the wind behind you to make it sound good," says another.

 

There are some huge differences between the EPA mileage estimates and the AAA numbers. For instance, a BMW Z4, rated at 21 miles per gallon city and 29 highway by the EPA gets only 14.5 miles per gallon in the AAA tests.

 

The popular Chrysler PT Cruiser, also rated at 21 city and 29 highway by the EPA, got a AAA average of 17.5 miles per gallon.

 

And the GMC Sierra, with an EPA rating of 16 city and 21 highway, got an auto club number of 15.3 miles per gallon.

 

The problem, says AAA, is that the federal government does not test cars in real world situations and doesn't factor in things like running the air conditioner or driving in stop-and-go traffic. Most tests are conducted in labs with the engines already warmed up, the speed kept below 60 miles an hour.

 

Now, two members of Congress have introduced legislation to change EPA testing methods.

 

"They have a statement that says, 'your actual mileage may vary,'" says the bill's co-author Rep. Rush Holt, D-N.J. "They should say, 'your actual mileage bears no relationship to these numbers in the window.'"[/quote']

 

That last bit was pretty funny. But if you take that information and figure in what was discussed in a recent thread Here it makes one wonder. An LS1 hybridV8 Z may be able to beat out a BMWZ4 in gas milage?! I even bet my carbed Z will beat that number when I get the 4 speed in it. Seems like auto manufacturers are working backwards making more gas consuming machines.

[JMortensen]

I keep seeing this hybrid Accord commercial that gets like 37 hwy, and I think that that is REALLY unimpressive. I know, it has a V6, but it still seems unimpressive. And WTF is going on when car companies are touting 30 mpg on a super aerodynamic subcompact car? Seems to me my friends '85 VW Rabbit diesel got 45-50 mpg, and that was in '85. As I posted before on another thread, I put a cam and header and exhaust on my 2.4L Toyota 2wd truck and got it into the low 30's, and that's a pickup truck dragging around a windbreak behind the cab...

 

I'm not one to shoot for mpg, but it really seems like doubling the mpg on these little commuter sedans should be easy to do. Maybe I'm just not remembering correctly, but weren't they were getting about the same mpg out of these same models of car when they were using carburetors and had much worse aerodynamics???

[Guest tony78_280z]

I keep seeing this hybrid Accord commercial that gets like 37 hwy' date=' and I think that that is REALLY unimpressive. I know, it has a V6, but it still seems unimpressive.

Maybe I'm just not remembering correctly, but weren't they were getting about the same mpg out of these same models of car when they were using carburetors and had much worse aerodynamics???[/quote']

Well, all those emissions controls sacrificed alot of performance and gas milage thus the primary reason to change to EFI, to help control emissions. But it does seem to be un impressive. Those GEOs claimed 56mpg. I was seein a girl who said she got about 47mpg out of it in the city. Compare that to the 37mpg hyrbrid. It seems like they are working backwards to me. Or they just don't care.

[Sparks280zt]

VW Rabbit!!! We have an old shatty pick up version that my dad uses to haul trash off in. That baby gets 50 mpg easy. We just fill it up and dont have to wry about putting any more fuel in it for a long time.

[Guest Aaron]

Yeah, something seems wrong. I get 16-17mpg in my 98 Nissan King Cab 4x4 in the city and highway without changing anything. I found I could get around 19mpg h'way by lowering the tailgate and folding the mirrors in. Seems like the manufacturers could spend a little time in a wind tunnel and pick up some nice h'way numbers without sacrificing the look of the car.

[CruxGNZ]

You think that's bad... I always click my odometer when I fill up and check my miles per gallon each fill up. In my 2002 Chevy S-10 Crew Cab, I get 11.7 MPG city (the lowest I've recorded) and 17 MPG highway. With these gas prices sky rocketing, and work is slow, my pocket book is hurting

 

As for the article above, I think AAA has it right. The EPA should test vehicles in 'real life' situations.

 

!M!

[Pop N Wood]

The EPA tests are not suppose to mimic "real world driving". They are meant to be a controlled test that allows you to compare MPG numbers on different vehicles in a fair manner. It almost doesn't matter what you do to test a car, as long as you test them all in exactly the same manner. Otherwise the results are hard to interpret.

 

Honda did not make an Accord hybrid for economy reasons as much as performance reasons. Electric motors develop full torque off the line. Thus you can build a gas engine that is tuned for high revs and use the electric boost to still have a drivable car. Any increase in MPG is of secondary importance.

 

A lot of people made very high MPG cars in the past. But it didin't take long for car manufactures to learn they didn't sell. Not many people are willing to give up AC or even an automatic transmission to grab a few MPG. Now days everything is about super sized vehicles. So I guess there is a different standard, gain mileage without sacrificing too much performance or comfort.

 

And be careful about making the EPA tests too realistic. If Kerry had gotten in office we could have been looking at more strict gas mileage laws. Make those tests as optimistic as possilbe!!!

[Guest tony78_280z]

And be careful about making the EPA tests too realistic. If Kerry had gotten in office we could have been looking at more strict gas mileage laws. Make those tests as optimistic as possilbe!!!

LOL One more reason to not vote for him in four years should he be dumb enough, or if Hillary will let him run.

 

If the EPA tests don't reflect real world driving, and everyone knows this (which I didn't until today) then it is a strait out lie for sales people to say that such and such vehicle gets XXmpg when it wont get near that amount. That is just like saying it has 20,300 miles when it has double that. And when they say "actual mpg may vary" you think the amount you are being quoted is an average.

[Guest comeandzpa]

The numbers on the sticker from the EPA are somewhat misleading, but they are meant to be a means of comparison as much as they're a measurement of the milage you'll get. The EPA testing methods really aren't realistic. The highway test never exceeds 60 MPH, and maintains a speed of 55 MPH for a short amount of time; they never go through a test where the A/C is blasting, you're going 70, and then need to pass a truck in a short passing zone. The tests are highly standardized but not necessarily accurate. Even the EPA realizes that their numbers will fluctuate and are not an exact science - they give a range on the window sticker. Look closely under the large numbers that manufacturers and salesmen quote. They have a statement under those numbers that says something to the extent of "during testing, this vehicle averaged between ___ and ___ mpg." The large number that they use for advertising is the average of those numbers. For example, a vehicle with a highway rating of "34" will have a range of milage that averages to 34. This range might be 30-38, and it might be 20-48. Whatever the range is, its the average that is used on the sticker. That's why some vehicles perform better than the sticker says and some perform worse - the ones with a smaller range are more likely to perform at or near the claimed milage than a car with a widely varying range.

 

if any of that made sense.....go me for overcoming a mind-numbing workday.

[Chaparral2f]

How dare you say these things?? Everybody knows that the auto companies love us:).... almost as much as the oil companies do.

[Guest bastaad525]

I used to worry all the time, that my 240z Turbo only got like 17-19mpg, and my '91 Sentra averaged 25.5 every tankfull... like wtf?? this seemed so low... but then I talk to other people and get their real world mpg and find that it's really not that bad. So seeing AAA come out with a list like this is no big surprise to me... especially in SoCal, who really ever gets the MPG that the EPA says they should?

 

I think that simple fact that 240's are so light compared to 95% of cars out there today... it makes perfect sense that if driven sensibly, even a high power V8 Z or turbo Z can get better gas mileage than a similar powered present-model car. 18 mpg's out of a 260-270 est. HP car that sees 90% street driving and get's floored at every opportunity seems pretty good to me and 26 mpg's out of the 2 liter Sentra (also driven with a lead foot at every opportunity) is nipping right at the heels of the 1.6 (or is it 1.8?) liter Corolla, which is supposed to be one of the high gas mileage leaders... not bad at all

[crazy280]

I agree, I think they should use a more realistic test. Even if it's mostly for comparison, they should still let us compare real numbers instead of inflated ones. I want to know what I'm buying (well...I couldn't afford a new car anyhow, go figure ). I think the trend that cars keep getting bigger and heavier and heavier and heavier has something to do with the stagnant mpg numbers in modern cars. I mean, the newer "beetle" weighs like 2900 lbs, hello that's almost double the original car, and the new "mini cooper" weighs HOW much? Geeez. Also, I keep hearing people mention that hybrids don't get as great of mileage as they should, like they should be record shattering or something. The point of hybrids is to be slightly more fuel efficient, but DRASTICALLY cleaner burning. Hence the PZEV classification (partial zero emissions vehicle). Although there is a correlation between the two, gas mileage and emissions are not always together like you'd think. For example, diesels get excellent MPG because they are more efficient than a gasoline engine can ever be (can't remember the formula, sorry), but they are also nasty polluters.

[GabeRoc]

IIRC, diesels are better for the enviroment than gas engines. the real issue with diesels, and the reason they are not more widely used, has to do with what people want to buy. as it has been mentioned few people are willing to pay the cost in comfort to have a high MPG car. simmilarly, few people are willing to deal with the noise, smaller RPM band and waiting that long minute in the winter for glow plugs to do their thing in the name of a 'cleaner' enviroment.

 

-gabe

[Pop N Wood]

Diesels have excessive NOx emissions and I think particulate (soot) emissions too. Diesel manufactures are constantly battling the EPA to prevent them from regulating diesels into extinction.

[johnc]

A digression...

 

While working at an aerospace company I had to deal with a cost accountant while writing some accounting software. They guy had just bought a new Suzuki Swift and was constantly bragging about how he was getting 36 mpg driving to a from work. It got to be really irritating to me and the other programmers working on this project. So, I decided to do something about it.

 

Once a week for a month I added 1 gallon of gas to the Suzuki's fuel tank. Mr. Cost Accountant began crowing about how his car, "now that the engine was broken in" is getting 48 mpg! And then, after a month, I stopped.

 

The next week Mr. Cost Account was concerned. His fuel mileage had dropped 25% and he felt something was wrong with the car. Over the next three months the car went back to the dealer at least half-a-dozen times while Mr. Cost Accoutant fought with Suzuki to get his car "fixed." He lost that war and was a beaten man.

 

After a year he traded the car in on a Toyota Starlet.

[BillZ260]

Devious!

[patzky1]

From a Cali gov't site:

 

"For the same load and engine conditions, diesel engines spew out 100 times more sooty particles than gasoline engines. As a result, diesel engines account for an estimated 26 percent of the total hazardous particulate pollution (PM10) from fuel combustion sources in our air, and 66 percent of the particulate pollution from on-road sources. Diesel engines also produce nearly 20 percent of the total nitrogen oxides (NOx) in outdoor air and 26 percent of the total NOx from on-road sources."

 

- This sounds like California-style diesel bashing. My question is: What percentage of the NOx in outdoor air is from gassers? How about PM5 and PM10? How do these relate when volume of gassers and diesels are factored in?

 

- However, Don't forget... when diesel enines are run at maximum capacity they tend to spew out the black stuff (carbon black soot, oil, unburnt fuel). At the same time, cars' emissions maintain about the same composition (RH and NOx go up a little) with different power settings.

 

Oh, and I thought everybody knew not to trust the mpg statements at the dealer. Averaging multiple sources is the way to go IMHO.

 

Pat

[dmyntti]

I always check my gas mileage between fill ups. I do almost all freeway driving around 70-75 mph. I routingly get better mileage then the sticker indicated. I do notice that cruise control adds about 5% to the gas mileage. My 99 Neon with DOHC engine and 5 speed got 38 mpg if I used midgrade and 33 if I used standard grade gas. My current car an 04 Chevy Aveo gets about 33 mpg no matter what fuel I use. I am somewhat disappointed by the mileage of the Aveo as the Neon was bigger faster and better looking and still got better mileage but the Aveo's mileage rating from the sticker is 33 and I do drive it too fast on the highway.

 

I have always found that the mileage ratings on new cars are close if you are driving a manual trans and drive at a steady rate of speed. But the automatics really seem to hurt the mileage of cars with small engines (as indicated on the sticker).

[BrandonsZ]

On the freeway at 62mph (about the average maximum speed I could go on a slight grade or with a headwind) with a 1986 Chevy Sprint (similar to the Geo Metro, but older).

 

It had a 1.0L 3 cylinder yes 3 cylinder suzuki engine. It was a carburated 2bbl with 1 primary and 2 secondary bore.

 

Unofficial 0-60 was 23 seconds.

 

Could not go 65 in 5th unless you were on flat land. But it could go 75 in 4th at 4500rpm

 

But it never got less than 45 MPG for the 75kmi I had it. ~ 1800lbs.

 

What happened to quality engineering such as this?

[crazy280]

Unofficial 0-60 was 23 seconds

LOL nice!