If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Are MPG ratings much less accurate then they used to be?
When I bought my old Concorde in 94 the MPG ratings were pretty much spot
on, the car got 22 in daily driving and 29 on long highway trips which is what the window sticker claimed. The MPG ratings for the new 300C is 17 city/25 highway which isn't even close to the real values, I'm getting 15-16 in daily driving, just did a 220 mile round trip yesterday and it peaked at 20 MPG. The article on hybrids (quoted in another thread) also mentions that the real mileage is nowhere near the sticker values. So my questions are these, has the method for determining the MPG ratings for cars changed in the last 10 years? Have manufacturer's gotten better at gaming the system? How do they determine the MPG ratings? It's hard to see how Chrysler managed to come up with a 25 MPG highway rating on the 300C unless they did the test on a road that was down hill all the way. |
Ads |
#2
|
|||
|
|||
AC is off during tests. That is why hybrids results are ridiculous. As for
the Hemi, perhaps it was optimized to turn off extra cylinders during the test and your driving habits do not mirror those test circumstances. "General Schvantzkoph" > wrote in message news > When I bought my old Concorde in 94 the MPG ratings were pretty much spot > on, the car got 22 in daily driving and 29 on long highway trips which is > what the window sticker claimed. The MPG ratings for the new 300C is 17 > city/25 highway which isn't even close to the real values, I'm getting > 15-16 in daily driving, just did a 220 mile round trip yesterday and it > peaked at 20 MPG. The article on hybrids (quoted in another thread) also > mentions that the real mileage is nowhere near the sticker values. So my > questions are these, has the method for determining the MPG ratings for > cars changed in the last 10 years? Have manufacturer's gotten better at > gaming the system? How do they determine the MPG ratings? It's hard to see > how Chrysler managed to come up with a 25 MPG highway rating on the 300C > unless they did the test on a road that was down hill all the way. > |
#3
|
|||
|
|||
"General Schvantzkoph" > wrote in message news > When I bought my old Concorde in 94 the MPG ratings were pretty much spot > on, the car got 22 in daily driving and 29 on long highway trips which is > what the window sticker claimed. The MPG ratings for the new 300C is 17 > city/25 highway which isn't even close to the real values, I'm getting > 15-16 in daily driving, just did a 220 mile round trip yesterday and it > peaked at 20 MPG. The article on hybrids (quoted in another thread) also > mentions that the real mileage is nowhere near the sticker values. So my > questions are these, has the method for determining the MPG ratings for > cars changed in the last 10 years? Have manufacturer's gotten better at > gaming the system? How do they determine the MPG ratings? It's hard to see > how Chrysler managed to come up with a 25 MPG highway rating on the 300C > unless they did the test on a road that was down hill all the way. The government determines the fuel consumption ratings not the Manufacturer. The tests are conducted on a flat surface without using air conditioning, and using average temperatures 70 - 80 degrees. And does not factor in, stop and go driving ,or different road grades. |
#4
|
|||
|
|||
On Mon, 18 Jul 2005 14:02:45 +0000, Art wrote:
> AC is off during tests. That is why hybrids results are ridiculous. As for > the Hemi, perhaps it was optimized to turn off extra cylinders during the > test and your driving habits do not mirror those test circumstances. Hard to believe that AC makes a 25% difference in a 4000lb car. The flat surface for the government tests could be the reason for the huge difference. 300Cs are very heavy and New England (where I live) is very hilly even on highways. Lugging a 300C up a hill probably puts enough strain on the system that all 8 cylinders are engaged which means that you are going to use much more energy going up a hill then you get back going down the other side because the engine is operating in it's less efficient mode on the upside of the hill. I wonder how hybrids behave on hills. On the one hand a true hybrid like the Toyotas will have to engage it's gas engine more on the other hand they recover more energy on the down side of hills because of the regenerative breaking. |
#5
|
|||
|
|||
Actually MPG is determined by unused energy that is left in the emissions it
is a chemical analysis with factors of weight and other physics that overall determines the MPG all this is done on a dyno. in a very controlled lab. I used to know the formula (sorry be awhile since I worked in the lab) the only way to truly achieve the listed MPG is with a lot of down hill driving. "General Schvantzkoph" > wrote in message news > When I bought my old Concorde in 94 the MPG ratings were pretty much spot > on, the car got 22 in daily driving and 29 on long highway trips which is > what the window sticker claimed. The MPG ratings for the new 300C is 17 > city/25 highway which isn't even close to the real values, I'm getting > 15-16 in daily driving, just did a 220 mile round trip yesterday and it > peaked at 20 MPG. The article on hybrids (quoted in another thread) also > mentions that the real mileage is nowhere near the sticker values. So my > questions are these, has the method for determining the MPG ratings for > cars changed in the last 10 years? Have manufacturer's gotten better at > gaming the system? How do they determine the MPG ratings? It's hard to see > how Chrysler managed to come up with a 25 MPG highway rating on the 300C > unless they did the test on a road that was down hill all the way. > |
#6
|
|||
|
|||
In the hybrid, as soon as AC goes on, gas engine goes on. That is why EPA
test results are a joke. "General Schvantzkoph" > wrote in message news > On Mon, 18 Jul 2005 14:02:45 +0000, Art wrote: > >> AC is off during tests. That is why hybrids results are ridiculous. As >> for >> the Hemi, perhaps it was optimized to turn off extra cylinders during the >> test and your driving habits do not mirror those test circumstances. > > Hard to believe that AC makes a 25% difference in a 4000lb car. The flat > surface for the government tests could be the reason for the huge > difference. 300Cs are very heavy and New England (where I live) is very > hilly even on highways. Lugging a 300C up a hill probably puts enough > strain on the system that all 8 cylinders are engaged which means that you > are going to use much more energy going up a hill then you get back going > down the other side because the engine is operating in it's less efficient > mode on the upside of the hill. I wonder how hybrids behave on hills. On > the one hand a true hybrid like the Toyotas will have to engage it's > gas engine more on the other hand they recover more energy on the down > side of hills because of the regenerative breaking. |
#7
|
|||
|
|||
They never were accuate. Those tests are done by starting the vehicle up
and driving with out a load on a lift and run untill the tank is empty, There are no cold starts, (just one start up) no a/c or stop and go traffic. Glenn Beasley Chrysler Tech |
#8
|
|||
|
|||
I don't recall what the EPA MPG ratings were for our '02 300M, but
driving back from Chicago to W. Michigan yesterday w. A/C on (outside temp. in the 90s) the EVIC showed an average of a little over 27mpg. BTW, does the grade (or brand) of gasoline affect mpg? I sometimes use 89, but mostly 87. Perce On 07/18/05 02:02 pm damnnickname tossed the following ingredients into the ever-growing pot of cybersoup: > They never were accuate. Those tests are done by starting the vehicle up > and driving with out a load on a lift and run untill the tank is empty, > There are no cold starts, (just one start up) no a/c or stop and go > traffic. |
#9
|
|||
|
|||
"Percival P. Cassidy" > wrote in message ... > > BTW, does the grade (or brand) of gasoline affect mpg? I sometimes use 89, > but mostly 87. > > Perce > No, except if the motor is into serious knocking. Too much octane is a waste of money and resources. Richard. |
#10
|
|||
|
|||
On Tue, 19 Jul 2005, "Richard" > wrote: > > BTW, does the grade (or brand) of gasoline affect mpg? I sometimes use 89, > > but mostly 87. > No, except if the motor is into serious knocking. Too much octane is a > waste of money and resources. Outdated info, no longer correct. All modern engines use knock sensors. Depending upon how the knock sensor and ignition timing control is implemented and calibrated, using fuel of higher octane *can* improve mileage by permitting more spark advance. Whether the increase in mileage balances the increased cost of higher-octane fuel is situational. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
USGP Farce - hit them in their ratings chart | mcewena | Simulators | 6 | June 24th 05 10:52 PM |
Green Weenie SUV ratings | HarryS | Jeep | 3 | April 6th 05 02:24 AM |
Safety ratings of classic VWs... | [email protected] | VW water cooled | 4 | March 28th 05 10:42 PM |
New AI ratings for NR03 for 2005? | TlgtrProd | Simulators | 0 | January 26th 05 02:32 PM |