Ouch my mileage sure drops at speed

[Scouzer]

Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

When I was driving through the city, the speed limit was between 44 and 56mph (converted from KMPH). In about 20 miles of driving with this, including three red lights (complete stops) and numerous times speeding up and slowing down, I managed 42mpg.

After this, I finally got out on to the open highway where the speed limit is 68mph. I turned on the cruise control at exactly 68mph, and watched the fuel economy. Over the next two hours my economy dropped and averaged at 31mpg.

Ouch. Sucks. And it happens every time.

Why don't they make 5th gear higher? My car turns at about 2700rpm to maintain 68mph, seems higher than necessary...

 

[Pepsi90919]

31 mpg is bad? and wtf are you saying everything in imperial?

 

[Scouzer]

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

 

[Cattlegod]

Originally posted by: Scouzer

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

wtf is kmph?

 

[Kntx]

It's not the rpm, it's the wind resistance. It really starts kicking up after about 60. Try going 60 even and check the difference.

 

[Scouzer]

Originally posted by: Cattlegod

Originally posted by: Scouzer

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

wtf is kmph?

I think we both know its KPH you twit.

KMPH just makes more sense as an acronym, IMO.

And yes 31mpg sucks.

 

[spidey07]

That's why many cars come with 6 speeds these days.

 

[b0mbrman]

Originally posted by: spidey07
That's why many cars come with 6 speeds these days.

The type of cars that I've driven w/6 gears didn't do it for the sake of fuel economy

 

[Mark R]

Dynamic aerodynamic drag sucks, doesn't it.

Go 20% faster, fuel economy drops 40%

Unless your car has the aerodynamics of an aircraft or F1 car, it'll hit a sweet spot at around 50-60 mph. Go over that, and it's downhill all the way, regardless of transmission configuration.

 

[iamaelephant]

Originally posted by: Scouzer

Originally posted by: Cattlegod

Originally posted by: Scouzer

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

wtf is kmph?

I think we both know its KPH you twit.

KMPH just makes more sense as an acronym, IMO.

And yes 31mpg sucks.

Putting the "p" into any unit acronym is stupid, and so is using archaic units to please stubborn Americans. And KPH is possibly the stupidest unit acronym ever conceived. It's km/h, the "m" is absolutely essential.

 

[spaceman]

31 lol.
i wish i got that downhill.

 

[BUTCH1]

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

When I was driving through the city, the speed limit was between 44 and 56mph (converted from KMPH). In about 20 miles of driving with this, including three red lights (complete stops) and numerous times speeding up and slowing down, I managed 42mpg.

After this, I finally got out on to the open highway where the speed limit is 68mph. I turned on the cruise control at exactly 68mph, and watched the fuel economy. Over the next two hours my economy dropped and averaged at 31mpg.

Ouch. Sucks. And it happens every time.

Why don't they make 5th gear higher? My car turns at about 2700rpm to maintain 68mph, seems higher than necessary...

My GM has one of those MPG readout as well, your using it improperly, stop resetting the damm thing and if you are turning 2700
@68MPH go ahead and shift into 5th gear, it's OK..Hell my old 95 escort@2700RPM would have you at almost 80 and that was with
a 4 speed auto..

 

[Scouzer]

Originally posted by: iamaelephant

Originally posted by: Scouzer

Originally posted by: Cattlegod

Originally posted by: Scouzer

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

wtf is kmph?

I think we both know its KPH you twit.

KMPH just makes more sense as an acronym, IMO.

And yes 31mpg sucks.

Putting the "p" into any unit acronym is stupid, and so is using archaic units to please stubborn Americans. And KPH is possibly the stupidest unit acronym ever conceived. It's km/h, the "m" is absolutely essential.

Actually, the thoughts in my mind was using archaic units to please stupid Americans.

Butch1, I assure you that's the RPM my car is at in 5th.

 

[iamaelephant]

Originally posted by: Scouzer

Originally posted by: iamaelephant

Originally posted by: Scouzer

Originally posted by: Cattlegod

Originally posted by: Scouzer

Originally posted by: Pepsi90919
31 mpg is bad? and wtf are you saying everything in imperial?

eh? US gallons (I think) and no one here understands kmph.

wtf is kmph?

I think we both know its KPH you twit.

KMPH just makes more sense as an acronym, IMO.

And yes 31mpg sucks.

Putting the "p" into any unit acronym is stupid, and so is using archaic units to please stubborn Americans. And KPH is possibly the stupidest unit acronym ever conceived. It's km/h, the "m" is absolutely essential.

Actually, the thoughts in my mind was using archaic units to please stupid Americans.

Butch1, I assure you that's the RPM my car is at in 5th.

I almost typed "stupid" but decided I'm sick of being banned Some Americans are sensitive to having their wittle feewings hurt I've found.

 

[BUTCH1]

Is that CRPM?? (Canada's RPM)..No modern vehicle will turn 2700@68 MPH unless it's been modified for racing and no
auto will get WORSE MPG @ cruising speed than in traffic (except hybrids of course) please, drag your owners manuel
into the crapper and read it before any more posting, you lack the automotive knowledge that a 10 year old in the USA
takes for granted, making YOU look stupid..

 

[MercenaryForHire]

Originally posted by: BUTCH1
Is that CRPM?? (Canada's RPM)..No modern vehicle will turn 2700@68 MPH unless it's been modified for racing and no
auto will get WORSE MPG @ cruising speed than in traffic (except hybrids of course) please, drag your owners manuel
into the crapper and read it before any more posting, you lack the automotive knowledge that a 10 year old in the USA
takes for granted, making YOU look stupid..

Pursuit GT = 25.1" tire diameter, 0.69:1 gear ratio in 5th, 3.84:1 final drive.

Do the math yourself if you like.

- M4H

 

[Mallow]

Odd thing is this, I own a ford mustang... going around town the thing gets about 21MPG, when I go on trips where I travel about 80-85MPH for the entire tank of gas I get about 22MPG. Nothing really seems to affect it so I don't worry about it

 

[BUTCH1]

Fuel consumption 2.2 City: 9.5 L/100 km (30 mpg Imperial)
Hwy: 6.1 L/100 km (46 mpg Imperial)
Fuel consumption 2.4 City: 9.9 L/100 km (29 mpg Imperial)
Hwy: 6.6 L/100 km (43 mpg Imperial)
from These specs,
no way you can get that MPG turning 2700@68, hell you'd be close to redline@ 100..

 

[overst33r]

Originally posted by: Mallow
Odd thing is this, I own a ford mustang... going around town the thing gets about 21MPG, when I go on trips where I travel about 80-85MPH for the entire tank of gas I get about 22MPG. Nothing really seems to affect it so I don't worry about it

You could be in the high 20s if you obeyed the speed limit...if you drove 10% below the limit you could probably see a 30... I'm guessing you drive a V6 version?

 

[compnovice]

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

...........

You calculated your mileage within 0.2mpg of your fuel economy gauge....... wow....impressive...

oh wait.... Shens....

 

[MercenaryForHire]

Originally posted by: compnovice

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

...........

You calculated your mileage within 0.2mpg of your fuel economy gauge....... wow....impressive...

oh wait.... Shens....

(Odometer / Fuel Added) = Est. MPG?

- M4H

 

[Scouzer]

Originally posted by: MercenaryForHire

Originally posted by: compnovice

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

...........

You calculated your mileage within 0.2mpg of your fuel economy gauge....... wow....impressive...

oh wait.... Shens....

(Odometer / Fuel Added) = Est. MPG?

- M4H

Correct. It's not bang on, but to have both measurements so close it's obviously fairly accurate.

Butch1, shut up. I'll see if I remember to get you a picture on my drive home from work.

 

[mercanucaribe]

Originally posted by: BUTCH1
Is that CRPM?? (Canada's RPM)..No modern vehicle will turn 2700@68 MPH unless it's been modified for racing and no
auto will get WORSE MPG @ cruising speed than in traffic (except hybrids of course) please, drag your owners manuel
into the crapper and read it before any more posting, you lack the automotive knowledge that a 10 year old in the USA
takes for granted, making YOU look stupid..

My 240sx was spinning at almost 3000 rpm at 70mph.

This thread makes no sense. People are bashing him for using imperial units, when this is an American forum, and he was trying to make his post relevant to more people. I sure as hell wouldn't have any idea what he was talking about if he posted his L/100km.

And then there are people spewing BS about how no car should be turning at 2700rpm at 68mph, which obviously isn't true.

Then, not so bad, are the ones saying that RPM doesn't matter, only aerodynamics. Most cars are still geared for optimal gas mileage at 55mph in top gear, so a higher gear could improve gas mileage if the engine is powerful enough at lower rpm. I believe that 6 speed manuals do have two overdrives in general.

 

[compnovice]

Originally posted by: MercenaryForHire

Originally posted by: compnovice

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

...........

You calculated your mileage within 0.2mpg of your fuel economy gauge....... wow....impressive...

oh wait.... Shens....

(Odometer / Fuel Added) = Est. MPG?

- M4H

 

[sao123]

Originally posted by: Scouzer
Car: 2006 Pontiac Pursuit GT

I have an on board fuel economy gauge. It is very accurate. I have tested it on two fuel tanks in the past, and it was within .2 mpg of my calculations.

When I was driving through the city, the speed limit was between 44 and 56mph (converted from KMPH). In about 20 miles of driving with this, including three red lights (complete stops) and numerous times speeding up and slowing down, I managed 42mpg.

After this, I finally got out on to the open highway where the speed limit is 68mph. I turned on the cruise control at exactly 68mph, and watched the fuel economy. Over the next two hours my economy dropped and averaged at 31mpg.

Ouch. Sucks. And it happens every time.

Why don't they make 5th gear higher? My car turns at about 2700rpm to maintain 68mph, seems higher than necessary...

Several fuel economists suggested that they make 6th gear which would run at 65mph at 1800rpms thus making fuel economy peak at 65 instead of 55... but thent he government claimed that would encourage people to drive 65mph all the time thus creating a more sufficient speeding problem...
:thumbsdown: