[Hawkeman]

I got my "Software Upgrade" recall letter a couple of days ago for the inability to properly sense thermostat issue.

I also never got the exhaust pinging fixed so I'll kill two birds with one stone when I go back to the dealer for the recall.

[johhnyx]

Hi,
I just bought my wife a Compass last Thursday. As of that day, there were only three at dealerships in all of Western NY, so we pounced on it. We drove it to our cottage (about a 60mi trip 1way) via mostly hilly backroads for fun, and a ton of stop/go city driving in between. It's the CVT model. While she sometimes kept a lighter foot on the highway parts, she stomped it a few times.

We just crossed 300 mi on the way back and I filled it up. We managed a tad under 24MPG, which I didn't think was too back for a vehicle not yet broken in. So far, we're super satisfied, although I wish they didn't "dumb down" the CVT and give it "pseudo-shift points" to make people think that it's like a regular auto.

Cheers,
John

[fred2]

Don Smith, on Jul 8 2006, 06:17 PM, said:

My new Caliber SXT with CVT now has about 1500 miles and I've kept precise records.

The sticker says "26/30". In real life, I'm getting 22 in the city and 27 on the highway. That's with the air conditioner running full time in the Dallas, TX heat.

That is very interesting.
My 1999 Intrepid ES with the 3.2L V6 and 225 HP gets real 22 mpg city and 28 highway and is big and fast. Aren't these Calibers supposed to be fuel effecient?

[Hawkeman]

That's weird, mine is still 24-30 depending on how many hghway miles are involved. Mine is also a 2.0 SXT and I generally pack around a lot of tools in the back. I'm sitting at about 4300 mi. if that helps.

I also "give her all she's got" quite often with the air on full blast here in Louisiana.

Good luck with your fuel mileage in the future.

[Stratuscaster]

Rent another Caliber and see if it does the same thing.

If not, take your car back and get a new one.

[68SportFury]

That might be interesting--I don't think I've ever heard of anyone trying to get a car replaced for poor fuel economy.

None of these stories make me want to run out and buy a Caliber. Fortunately, the Stratus only has 58,800 miles on it and the Daytona just keeps on running at an estimated 191,400.

[55Plaza]

moparknighthawk, on Jul 3 2006, 09:11 AM, said:

The 75-80 MPH will hurt gas mileage quite a bit. You cannot expect good gas mileage when going fast

Sorry to argue with you 'moparknighthawk', but other than my '78 Monaco, I consistently got (at least) 3-5 mpg better mileage at 75-80 mph than 60 mph and the best mileage in my '79 D150 was at an estimated 115 mph (since the speedo ran out at 80 mph).

I just came back from a trip that included cruising at 75-81 mph from Edmonton to Calgary - that portion of my journey I got 29.81 mpg vs. 25.76 (averaging 65 mph).

[CanadianJeepYJ]

55Plaza, on Aug 9 2006, 03:52 PM, said:

Sorry to argue with you 'moparknighthawk', but other than my '78 Monaco, I consistently got (at least) 3-5 mpg better mileage at 75-80 mph than 60 mph and the best mileage in my '79 D150 was at an estimated 115 mph (since the speedo ran out at 80 mph).

I just came back from a trip that included cruising at 75-81 mph from Edmonton to Calgary - that portion of my journey I got 29.81 mpg vs. 25.76 (averaging 65 mph).

Physically impossible....less energy to go faster? You may have solved the earths energy problems.

It takes less energy to move at a higher velocity where your energy is 1/2*m*v^2....good job.

[PillowPC]

flyusmc, on Jul 16 2006, 01:26 PM, said:

What other forum are you on? My dealer says there is not a recal on this car, and I tried entering the last 8 digets on the vin on the Dodge website and they said no recall exhists for this car.

Thanks,
-Andy

I have the same car as you Andy, and I got that recall notice in the mail a month ago. I bought my SXT Sport back in April 06, so Dodge may have made the needed changes at the production level, before most folks bought their Calibers.

Gah, I still need to get mine to the dealer for that flash :blink:

-Lee

[CanadianJeepYJ]

CanadianJeepYJ, on Aug 9 2006, 04:16 PM, said:

Physically impossible....less energy to go faster? You may have solved the earths energy problems.

It takes less energy to move at a higher velocity where your energy is 1/2*m*v^2....good job.

I have to say that I am somewhat wrong....it depends on the RPMs and not the speed of the vehicle.

[jstew314]

55Plaza, on Aug 9 2006, 04:52 PM, said:

Sorry to argue with you 'moparknighthawk', but other than my '78 Monaco, I consistently got (at least) 3-5 mpg better mileage at 75-80 mph than 60 mph and the best mileage in my '79 D150 was at an estimated 115 mph (since the speedo ran out at 80 mph).

I just came back from a trip that included cruising at 75-81 mph from Edmonton to Calgary - that portion of my journey I got 29.81 mpg vs. 25.76 (averaging 65 mph).

Here's a proposed explanation for consistently getting 3-5mpg higher at 75-80 mph than at 60 mph: The traffic and/or road conditions were worse when you were driving 60, and you were braking and accelerating much more, or it was hillier or the vehicle was loaded more heavily, or you had the tranny in a lower gear.

The horsepower required to overcome air resistance is equal to a constant times the speed cubed, so this does not go down with increasing speed, but increases with increasing speed. (The constant is dependent on the air conditions.) There could conceivably be details of the functioning of the engine and tranny that could actually give higher mph (in the same atmospheric conditions) at one vehicle speed which was slightly higher than another vehicle speed, but it really doesn't seem to be an explanation for the results you report.

Concerning your results on your Edmonton to Calgary trip, you compare two drives:

1. ". . . a trip that included cruising at 75-81 mph from Edmonton to Calgary - that portion of my journey I got 29.81 mpg. . ."

2. ". . . vs. 25.76 (averaging 65 mph)."

Could you provide a description of these two drives? For each drive: number of miles, number of gallons of fuel consumed, starting and ending points, terrain, road, traffic and weather conditions, date and time.

This post has been edited by jstew314: 14 August 2006 - 05:27 AM

[CanadianJeepYJ]

F = gamma*v

E = int(F dx)

How do you get v^3.....I forget that equation....is my E equation wrong?

You do make a very good point about the air resistence playing a big roll in gas mileage.

This post has been edited by CanadianJeepYJ: 14 August 2006 - 10:40 PM

[jstew314]

CanadianJeepYJ, on Aug 14 2006, 10:22 PM, said:

F = gamma*v

E = int(F dx)

How do you get v^3.....I forget that equation....is my E equation wrong?

You do make a very good point about the air resistence playing a big roll in gas mileage.

You don't get this from general considerations. It's evidently an empirical fact that the aerodynamic drag force is well fit by a proportionality to v^2, then you simply multiply by v to get the power. This gives v^3 for the power req'd to overcome air resistance. See the NASA link provided by Bob Sheaves.

http://space-power.g...a.html#AERODRAG

This post has been edited by jstew314: 15 August 2006 - 03:38 PM

[CanadianJeepYJ]

jstew314, on Aug 15 2006, 09:08 AM, said:

You don't get this from general considerations. It's evidently an empirical fact that the aerodynamic drag force is well fit by a proportionality to v^2, then you simply multiply by v to get the power (or intergarte wrt v if v is changing with time). This gives v^3 for the power req'd to overcome air resistance. See the NASA link provided by Bob Sheaves.

http://space-power.g...a.html#AERODRAG

[nerd alert]

F = -gamma*v -----> viscous resistance is appropriate for small objects or particles moving through a fluid at relatively slow speeds

F = -1/2*pho*A*Cd*v^2 ------> approximates the force experienced by an object moving through a fluid at relatively large velocity

One is for a small particle at slow speeds (mine) and a "large" object at large speeds (yours).

E propto int(v^2 dx) = int(v^2 dx/dt dt) = int(v^3 dt)

and to get the power get ride of the dt to get the loss of power which is proportional to v^3.

[/nerd alert]


Thanks jstew314

This post has been edited by CanadianJeepYJ: 15 August 2006 - 03:29 PM

[Bob Lincoln]

Quote

Ethanol does reduce gas mileage - I'd GUESS by about 7%.

Really? I've been using it for months, with zero change. Maybe it depends on the engine.

[DGC]

Bob Lincoln, on Aug 23 2006, 02:49 PM, said:

Really? I've been using it for months, with zero change. Maybe it depends on the engine.

Have you gone for a more conservative driving style?

[68SportFury]

The mileage I've gotten with the Daytona and the Stratus has usually been over a variety of different driving conditions--my commute is mostly highway, but sometimes that means 65 all the way and sometimes it means long stretches of wondering if I'll get out of second before I get off the Beltway.
I'll say this, though: I usually run about 65 mph on the highway and rarely break 70. I also don't punch it a lot and, on the Daytona, I don't slow down by downshifting unless I'm on a really slick surface.

Best to date: 40 mpg in the Daytona going to Englishtown and back in 1997, 32 in the Stratus during a normal commuting week. Average was about 32 in the Daytona when the odometer quit and average in the Stratus is about 29.

Fun fact: My mother has a Stratus equipped identically to mine, drives it a lot less and barely squeezes 20 mpg out of it. It's appalling...but then she's had it for over four years and only put 15,000 miles on it.