My MPG theory (Correct me if I'm wrong please)

[ATI RADEON 8500]

Is this how MPG works. The higher RPM the engine is running at the faster it consume gas? Or is it really based on how fast you are going?

When I'm driving my car and I see my RPM at around 3000rpm when I'm driving at 45 mph then when I increase my speed to 50-55 the RPM goes up to 4000. Then When I up my speed to 60 The RPM drops to 3000. So Does that mean I'm consuming less gas when driving at 60 mph because the RPM is lower?

The RPM number isnt accurate or acutal. but you get the idea dont you?

[porsch1909]

I trust you have an automatic, so your revs go down when ure auto changes gears

try 56mph. that is the speed at which you get the best fuel consumption.

But generally lower revs gives better fuel consumption


what figure you get for MPG?

[ScaryBinary]

Originally posted by porsch1909
try 56mph. that is the speed at which you get the best fuel consumption.

Why?

[porsch1909]

Just is...I am sure if i googled it i could find out.....

I am sure it has something to do with equilibrium though.....


A lot of lorries at limited to 56Mph for that reason though.

The speed makes more sense in KPH though...nice figure id imagine...

[porsch1909]

http://eartheasy.com/live_fueleff_graph.jpg


a wee graph heehehehe

http://eartheasy.com/live_fuel_efficient_driving.htm

linky....

cant actually find out why though....

90kmh is the speed....nicer number :p

[ukulele]

Actually the rpm the motor is running at is the best way to optimize fuel consumption. My Cadillac has an onboard computer display that shows both average and instantanious fuel consumption. The car get's it's best MPG at around 2200 rpm on level roads and 2800 RPM's on grades. Think of it this way, the more you depress the throttle, the more you use. If you have a car floored in fourth gear going up a hill at 2000 rpms you are using more gas per mile then if you have half throttle at 3000 rpms in third gear at the same speed. I have also noticed that contrary to what the manufactures say about cruise control, I get better average milage if I let it slow down going up hills and speed up going down. Keeping an even speed actually wastes gas going up short grades.

[j.m@talk]

Well if you had 7 tonnes of sand on the back seat, the speed & the RPM would be the same, however it would use heaps more fuel............

56Mph = 90Kph Which is plenty fast enough for trucks etc....... Its got nothing to do wiv MPG its got a lot to do with saftey.

The 55Mph limit was initially put into place in 1974 in response to OPEC's oil embargo.

So the optimal speed of your car is 55Mph.
Obviously the further the pedal is down the more "Open" the tap is & more fuel is guzzled :p

I get 25/27 Urban & 32/33 Rural @ sensible speeds. 23/25 Zoomin' along Kamakaze fashion ;)

:t

[mireland]

Originally posted by j.m@talk
Well if you had 7 tonnes of sand on the back seat, the speed & the RPM would be the same, however it would use heaps more fuel............

56Mph = 90Kph Which is plenty fast enough for trucks etc....... Its got nothing to do wiv MPG its got a lot to do with saftey.

The 55Mph limit was initially put into place in 1974 in response to OPEC's oil embargo.

So the optimal speed of your car is 55Mph.
Obviously the further the pedal is down the more "Open" the tap is & more fuel is guzzled :p




I get 25/27 Urban & 32/33 Rural @ sensible speeds. 23/25 Zoomin' along Kamakaze fashion ;)

:t

you know: you sounded pretty educated right then... :D

[j.m@talk]

Originally posted by mireland
you know: you sounded pretty educated right then... :D

Holey Moley! .......... Billy Bob go geet my clowns nose :p

[ScaryBinary]

Originally posted by porsch1909
http://eartheasy.com/live_fueleff_graph.jpg


a wee graph heehehehe

http://eartheasy.com/live_fuel_efficient_driving.htm

linky....

cant actually find out why though....

90kmh is the speed....nicer number :p

OK, but wouldn't it really depend on how your particular car is geared and what engine the car has in it? I don't believe ALL cars get the best fuel economy at 55 MPH.....

....But I'm no genius when it comes to cars (or anything else, now that I think about it....).

[j.m@talk]

Originally posted by ScaryBinary I don't believe ALL cars get the best fuel economy at 55 MPH.....


Well its near enough........ Yeah it depends on huge ammounts of differing stuff ............ One being your distance from sea level :rolleyes:

Obviously if you want to do all the calculations for the dude feel free :t

Lick finger ....... place in air; umm the wind is blowing that way ............. Not The wind is eminating from 165 Degs East .............. Freakin compooter geeks :rolleyes:



:D


:t

[nothing]

Originally posted by mireland
you know: you sounded pretty educated right then... :D

I was about to say the same thing! :D

[j.m@talk]

Law of averages ........... If I witter on enough, the likelyhood of been right was bound to happen at some point :rolleyes:

[mireland]

Originally posted by j.m@talk
Law of averages ........... If I witter on enough, the likelyhood of been right was bound to happen at some point :rolleyes:

http://www.fancysplace.com/smileys/youreright.gif

[ScaryBinary]

Originally posted by j.m@talk
Well its near enough........ Yeah it depends on huge ammounts of differing stuff ............ One being your distance from sea level :rolleyes:

Obviously if you want to do all the calculations for the dude feel free :t

Lick finger ....... place in air; umm the wind is blowing that way ............. Not The wind is eminating from 165 Degs East .............. Freakin compooter geeks
Ya, I imagine I'd get worse MPG with, for example, a body in the trunk.
:r

[mireland]

Originally posted by ScaryBinary
Ya, I imagine I'd get worse MPG with, for example, a body in the trunk.
:r


well that depends on the placement..if you put two bodies properly situated, you shouldn't notice any difference..







im not speaking from experience though... :D

[ukulele]

Well if you had 7 tonnes of sand on the back seat, the speed & the RPM would be the same, however it would use heaps more fuel............

Yes, if I had 7 tons of sand on the back seat this is true. :p

[j.m@talk]

How comes cos a ton is 100 Lbs Heavier than a tonne :eek:

[porsch1909]

The wee 1.5 deisel we have gives us 52MPG....rather good.

even though the official combined is 65....

But the 2.7 engine gives a rather handy 42MPG! But i think that optimum dieslel was put in and that costs even more money...

The americans have it good with fuel costs....they should try UK prices for a while :p

[j.m@talk]

We got the NHS tho .......... & I ain't swappin that for nowt :t

[COLN]

Since owning a Prius, I find my driving habits have changed with the regular vehicle. I don't let the car idle in construction zones if I can tell there is a long wait as it is easy to restart the engine. I coast when I can and I don't leave the car running when doing short errands such as getting the mail. I average 53-55mph with my Prius around town, 60 on long trips. Even with better driving habits, my Tacoma still only gets 28mpg. Guess which one stays in the drive way the most.

[j.m@talk]

& your point is ? .................."MY Prius Is good cos" ....................... :t

[ScaryBinary]

I find I save quite a bit on gas if I drive other peoples' Priuses.





Or is that "Prii?"

[j.m@talk]

Originally posted by ScaryBinary
I find I save quite a bit on gas if I drive other peoples' Priuses.





Or is that "Prii?"


No its called a "Skank" ................... Get used to it :-@

[mireland]

Originally posted by j.m@talk
No its called a "Skank" ................... Get used to it :-@

that's the tooth talkin' isn't it??? http://www.fancysplace.com/smileys/hang.gif

[j.m@talk]

Prius = Mirelands head, or a bridge, I need to talk to j00 boy .................... In a British way :rolleyes:

[mireland]

Originally posted by j.m@talk
Prius = Mirelands head, or a bridge, I need to talk to j00 boy .................... In a British way :rolleyes:

wow..you're just plain *****y now...:eek:

[j.m@talk]

Originally posted by mireland
wow..you're just plain *****y now...:eek:

Lando.................. You dare bring a Prius near me I will bring the dudes in .......


Kin Puff





:t

[mireland]

Originally posted by j.m@talk
Lando.................. You dare bring a Prius near me I will bring the dudes in .......


Kin Puff





:t

how about a dodge dart or an AMC pacer, a Gremlin perhaps???:p

[j.m@talk]

I'll give ya a 950 fiesta 1990........ It'll do what yas jeep job :t


Euro made ........... When the fuel is empty ...... Get another :p

[mireland]

Originally posted by j.m@talk
I'll give ya a 950 fiesta 1990........ It'll do what yas jeep job :t


Euro made ........... When the fuel is empty ...... Get another :p

no fanks...;)

[j.m@talk]

Originally posted by mireland
no fanks...;)

Easterns are Euros now according to Tony :t

[ukulele]

Originally posted by COLN
Since owning a Prius, I find my driving habits have changed with the regular vehicle. I don't let the car idle in construction zones if I can tell there is a long wait as it is easy to restart the engine. I coast when I can and I don't leave the car running when doing short errands such as getting the mail. I average 53-55mph with my Prius around town, 60 on long trips. Even with better driving habits, my Tacoma still only gets 28mpg. Guess which one stays in the drive way the most.

A dodge Tacoma pickup gets 28mpg? What did you do? Take the body off. ;)

[j.m@talk]

Originally posted by ukulele
A dodge Tacoma pickup gets 28mpg? What did you do? Take the body off. ;)

Nope just lies :t

[ScaryBinary]

Originally posted by ukulele
A dodge Tacoma pickup gets 28mpg? What did you do? Take the body off. ;)

A Toyota Tacoma gets 28 MPG. But a Dodge Tacoma just gets rusty.

[COLN]

28mpg it is but then I irritate absolutely everyone driving 45-50mph if I absolutely have to take the truck. I want a hybrid tacoma :( Driving the Prius I set the cruise at 55 and won't budge beyond that which also irritates those with lots of money to spend on gas.

[porsch1909]

IF you didn't use your cruise control you would get a better fuel consumption. And if you turned the AC off, and opened a window instead :p

[ATI RADEON 8500]

Acording to mythbuster.. The vechile that was driving with AC saved slightly more gas than those who drive with window down. :p

[ukulele]

Originally posted by ATI RADEON 8500
Acording to mythbuster.. The vechile that was driving with AC saved slightly more gas than those who drive with window down. :p


Depends if you are in traffic or not.

[genesound]

It's all bs... aerodynamics work differently for different sizes and shapes. You can't make a blanket statement that holds true for all vehicles. Even temperature, humidity,barometric pressure, all types of weather, and altitude change things :p

It took years of research just to break Mach 1 reliably and safely.

The whole problem is for the sophisticated societies to get off of fossil fuels :r