D
Dgethin
Guest
I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
economical speed to get the most MPG.
Many Thanks
economical speed to get the most MPG.
Many Thanks
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P
PeterD
Guest
On Wed, 22 Feb 2006 13:04:26 GMT, "Dgethin"
<[email protected]> wrote:
>I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
>economical speed to get the most MPG.
>Many Thanks
>
Stopped with the engine off?
What's economical for you may not be for others. Very subjective
except in that one case cited above.
<[email protected]> wrote:
>I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
>economical speed to get the most MPG.
>Many Thanks
>
Stopped with the engine off?
What's economical for you may not be for others. Very subjective
except in that one case cited above.
M
Mike Romain
Guest
It is usually and rpm rate, not speed you look at for the best mileage.
Engines have a 'sweet spot' where they pull the best using the least
amount of gas pedal to keep them at a steady speed. On my Jeep CJ7,
that is 2300 rpm or so. For me this works out at 65 mpg in 4th gear.
If I use 5th or overdrive, my rpm drops out of the sweet spot down to
1700 or so at 65 mph. This causes my engine to lug and I have to use a
lot of gas pedal travel to maintain a steady speed against wind or
inclines. Yes, I still have lots of pull in 5th, but... This costs me
about 5 mpg.
Different brands of fuel make a difference too. Some use a lot of
alcohol in them which cuts down on gas mileage.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)
Dgethin wrote:
>
> I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
> economical speed to get the most MPG.
> Many Thanks
Engines have a 'sweet spot' where they pull the best using the least
amount of gas pedal to keep them at a steady speed. On my Jeep CJ7,
that is 2300 rpm or so. For me this works out at 65 mpg in 4th gear.
If I use 5th or overdrive, my rpm drops out of the sweet spot down to
1700 or so at 65 mph. This causes my engine to lug and I have to use a
lot of gas pedal travel to maintain a steady speed against wind or
inclines. Yes, I still have lots of pull in 5th, but... This costs me
about 5 mpg.
Different brands of fuel make a difference too. Some use a lot of
alcohol in them which cuts down on gas mileage.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)
Dgethin wrote:
>
> I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
> economical speed to get the most MPG.
> Many Thanks
S
SnoMan
Guest
If you are serious about best possible MPG, keep it under 60 as it is
not very areo dynamic and drag increases a lot when you exceed 55 MPH
and sweet spot of not it will take more power to overcome it and it is
more noticable in light weigh 4x4 than heavy ones. Not that they are
not effected but a large percentage of power is used to overcome aero
dynamic drag in a small one than a bigger one at moderate speeds.
On Wed, 22 Feb 2006 09:12:57 -0500, Mike Romain <[email protected]>
wrote:
>It is usually and rpm rate, not speed you look at for the best mileage.
>
>Engines have a 'sweet spot' where they pull the best using the least
>amount of gas pedal to keep them at a steady speed. On my Jeep CJ7,
>that is 2300 rpm or so. For me this works out at 65 mpg in 4th gear.
>
>If I use 5th or overdrive, my rpm drops out of the sweet spot down to
>1700 or so at 65 mph. This causes my engine to lug and I have to use a
>lot of gas pedal travel to maintain a steady speed against wind or
>inclines. Yes, I still have lots of pull in 5th, but... This costs me
>about 5 mpg.
>
>Different brands of fuel make a difference too. Some use a lot of
>alcohol in them which cuts down on gas mileage.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>Canadian Off Road Trips Photos: Non members can still view!
>Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
>(More Off Road album links at bottom of the view page)
>
>Dgethin wrote:
>>
>> I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
>> economical speed to get the most MPG.
>> Many Thanks
not very areo dynamic and drag increases a lot when you exceed 55 MPH
and sweet spot of not it will take more power to overcome it and it is
more noticable in light weigh 4x4 than heavy ones. Not that they are
not effected but a large percentage of power is used to overcome aero
dynamic drag in a small one than a bigger one at moderate speeds.
On Wed, 22 Feb 2006 09:12:57 -0500, Mike Romain <[email protected]>
wrote:
>It is usually and rpm rate, not speed you look at for the best mileage.
>
>Engines have a 'sweet spot' where they pull the best using the least
>amount of gas pedal to keep them at a steady speed. On my Jeep CJ7,
>that is 2300 rpm or so. For me this works out at 65 mpg in 4th gear.
>
>If I use 5th or overdrive, my rpm drops out of the sweet spot down to
>1700 or so at 65 mph. This causes my engine to lug and I have to use a
>lot of gas pedal travel to maintain a steady speed against wind or
>inclines. Yes, I still have lots of pull in 5th, but... This costs me
>about 5 mpg.
>
>Different brands of fuel make a difference too. Some use a lot of
>alcohol in them which cuts down on gas mileage.
>
>Mike
>86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>88 Cherokee 235 BFG AT's
>Canadian Off Road Trips Photos: Non members can still view!
>Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
>(More Off Road album links at bottom of the view page)
>
>Dgethin wrote:
>>
>> I have a Suzuki Grand Vitara 2.0TD, I would like to know what is the most
>> economical speed to get the most MPG.
>> Many Thanks
Z
[email protected]
Guest
SnoMan wrote:
> If you are serious about best possible MPG, keep it under 60 as it is
If he is REALLY serious about best possible MPG, he should put a Hall
effect impeller type flow rate sensor in his gas line and use a GPS
receiver to calculate "true" speed (i.e. actual ground speed rather
than inferring speed from axle rotation rates). Relatively simple
software can then show in realtime exactly how much fuel is being
consumed per mile.
P
PeterD
Guest
On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
>
>SnoMan wrote:
>> If you are serious about best possible MPG, keep it under 60 as it is
>
>If he is REALLY serious about best possible MPG, he should put a Hall
>effect impeller type flow rate sensor in his gas line and use a GPS
>receiver to calculate "true" speed (i.e. actual ground speed rather
>than inferring speed from axle rotation rates). Relatively simple
>software can then show in realtime exactly how much fuel is being
>consumed per mile.
He will also have to measure that fuel return to the tank to get an
accurate reading...
>
>SnoMan wrote:
>> If you are serious about best possible MPG, keep it under 60 as it is
>
>If he is REALLY serious about best possible MPG, he should put a Hall
>effect impeller type flow rate sensor in his gas line and use a GPS
>receiver to calculate "true" speed (i.e. actual ground speed rather
>than inferring speed from axle rotation rates). Relatively simple
>software can then show in realtime exactly how much fuel is being
>consumed per mile.
He will also have to measure that fuel return to the tank to get an
accurate reading...
Z
[email protected]
Guest
PeterD wrote:
> On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
> >If he is REALLY serious about best possible MPG, he should put a Hall
> >effect impeller type flow rate sensor in his gas line and use a GPS
>
> He will also have to measure that fuel return to the tank to get an
> accurate reading...
Oooh, good point - I didn't think about that. These new-fangled cars
have vapor recovery, I forgot
[the only car I do any work on is older than I am - and doesn't have
anything remotely new-fangled except a synchromesh gearbox].
S
SnoMan
Guest
On 23 Feb 2006 17:30:17 -0800, [email protected] wrote:
>
>PeterD wrote:
>> On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
>
>> >If he is REALLY serious about best possible MPG, he should put a Hall
>> >effect impeller type flow rate sensor in his gas line and use a GPS
>>
>> He will also have to measure that fuel return to the tank to get an
>> accurate reading...
>
>Oooh, good point - I didn't think about that. These new-fangled cars
>have vapor recovery, I forgot
>
>[the only car I do any work on is older than I am - and doesn't have
>anything remotely new-fangled except a synchromesh gearbox].
The newer vehicle with trip computers actually monitor the fuel being
injected to determine MPG
>
>PeterD wrote:
>> On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
>
>> >If he is REALLY serious about best possible MPG, he should put a Hall
>> >effect impeller type flow rate sensor in his gas line and use a GPS
>>
>> He will also have to measure that fuel return to the tank to get an
>> accurate reading...
>
>Oooh, good point - I didn't think about that. These new-fangled cars
>have vapor recovery, I forgot
>
>[the only car I do any work on is older than I am - and doesn't have
>anything remotely new-fangled except a synchromesh gearbox].
The newer vehicle with trip computers actually monitor the fuel being
injected to determine MPG
W
Will Honea
Guest
On Fri, 24 Feb 2006 02:58:38 UTC SnoMan <[email protected]> wrote:
> On 23 Feb 2006 17:30:17 -0800, [email protected] wrote:
>
> >
> >PeterD wrote:
> >> On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
> >
> >> >If he is REALLY serious about best possible MPG, he should put a Hall
> >> >effect impeller type flow rate sensor in his gas line and use a GPS
> >>
> >> He will also have to measure that fuel return to the tank to get an
> >> accurate reading...
> >
> >Oooh, good point - I didn't think about that. These new-fangled cars
> >have vapor recovery, I forgot
> >
> >[the only car I do any work on is older than I am - and doesn't have
> >anything remotely new-fangled except a synchromesh gearbox].
>
>
> The newer vehicle with trip computers actually monitor the fuel being
> injected to determine MPG
A real quick and dirty would be to measure the injector pulse width.
Assuming instant opening, instant close and constant fuel pressure,
the fuel flow will be directly proportional to the on time.
Considerably less hassle and and a heck of a lot cheaper than directly
measuring fuel flow!
--
Will Honea
> On 23 Feb 2006 17:30:17 -0800, [email protected] wrote:
>
> >
> >PeterD wrote:
> >> On 23 Feb 2006 06:40:09 -0800, [email protected] wrote:
> >
> >> >If he is REALLY serious about best possible MPG, he should put a Hall
> >> >effect impeller type flow rate sensor in his gas line and use a GPS
> >>
> >> He will also have to measure that fuel return to the tank to get an
> >> accurate reading...
> >
> >Oooh, good point - I didn't think about that. These new-fangled cars
> >have vapor recovery, I forgot
> >
> >[the only car I do any work on is older than I am - and doesn't have
> >anything remotely new-fangled except a synchromesh gearbox].
>
>
> The newer vehicle with trip computers actually monitor the fuel being
> injected to determine MPG
A real quick and dirty would be to measure the injector pulse width.
Assuming instant opening, instant close and constant fuel pressure,
the fuel flow will be directly proportional to the on time.
Considerably less hassle and and a heck of a lot cheaper than directly
measuring fuel flow!
--
Will Honea
P
PeterD
Guest
On 23 Feb 2006 17:30:17 -0800, [email protected] wrote:
>
>Oooh, good point - I didn't think about that. These new-fangled cars
>have vapor recovery, I forgot
>
>[the only car I do any work on is older than I am - and doesn't have
>anything remotely new-fangled except a synchromesh gearbox].
I hear they've got syncros on all gears *including* first now! Cool...
<bg>
>
>Oooh, good point - I didn't think about that. These new-fangled cars
>have vapor recovery, I forgot
>
>[the only car I do any work on is older than I am - and doesn't have
>anything remotely new-fangled except a synchromesh gearbox].
I hear they've got syncros on all gears *including* first now! Cool...
<bg>
P
PeterD
Guest
On Fri, 24 Feb 2006 02:58:38 GMT, SnoMan <[email protected]> wrote:
>
>The newer vehicle with trip computers actually monitor the fuel being
>injected to determine MPG
Interfacing with the computer allows a lot of cool things like this.
The computer knows (as you pointed out) exactly how much fuel is being
sent to the engine at any time.
I may be possible to simply monitor the inject signal to the injectors
and determine the fuel usage, too.
Humm, I smell oppertunity here! <bg>
>
>The newer vehicle with trip computers actually monitor the fuel being
>injected to determine MPG
Interfacing with the computer allows a lot of cool things like this.
The computer knows (as you pointed out) exactly how much fuel is being
sent to the engine at any time.
I may be possible to simply monitor the inject signal to the injectors
and determine the fuel usage, too.
Humm, I smell oppertunity here! <bg>
P
PeterD
Guest
On Fri, 24 Feb 2006 07:16:33 GMT, "Will Honea" <[email protected]>
wrote:
>
>A real quick and dirty would be to measure the injector pulse width.
>Assuming instant opening, instant close and constant fuel pressure,
>the fuel flow will be directly proportional to the on time.
>Considerably less hassle and and a heck of a lot cheaper than directly
>measuring fuel flow!
Damn, there goes my opportunity...
Actually you do't have to assume instant opening/closing: the
opening/closing would be consistant so you'd only have to factor it
into the equation. I think you'll find fuel pressure is also
relatively constant too.
I'll be this could be done on a laptop and a few hours of programming.
wrote:
>
>A real quick and dirty would be to measure the injector pulse width.
>Assuming instant opening, instant close and constant fuel pressure,
>the fuel flow will be directly proportional to the on time.
>Considerably less hassle and and a heck of a lot cheaper than directly
>measuring fuel flow!
Damn, there goes my opportunity...
Actually you do't have to assume instant opening/closing: the
opening/closing would be consistant so you'd only have to factor it
into the equation. I think you'll find fuel pressure is also
relatively constant too.
I'll be this could be done on a laptop and a few hours of programming.
S
Slightly Lost
Guest
Just recently, PeterD told us:
> I hear they've got syncros on all gears *including* first now! Cool...
> <bg>
<<chuckle>>
Not in mine...
--
======================
Slightly Lost
'80 Toy 4x4
4" / 35" / 5.71 / locked F+R
"Never send a Mall Terrain to do a Swampers job."
8:46 RIP
> I hear they've got syncros on all gears *including* first now! Cool...
> <bg>
<<chuckle>>
Not in mine...
--
======================
Slightly Lost
'80 Toy 4x4
4" / 35" / 5.71 / locked F+R
"Never send a Mall Terrain to do a Swampers job."
8:46 RIP
Z
[email protected]
Guest
PeterD wrote:
> I hear they've got syncros on all gears *including* first now! Cool...
> <bg>
You know, I saw a car without a clutch pedal yesterday. And it did not
have a control to retard the spark either (at least none that I could
see sitting at the wheel).
W
Will Honea
Guest
On Fri, 24 Feb 2006 14:05:23 UTC PeterD <[email protected]> wrote:
> On Fri, 24 Feb 2006 07:16:33 GMT, "Will Honea" <[email protected]>
> wrote:
>
>
> >
> >A real quick and dirty would be to measure the injector pulse width.
> >Assuming instant opening, instant close and constant fuel pressure,
> >the fuel flow will be directly proportional to the on time.
> >Considerably less hassle and and a heck of a lot cheaper than directly
> >measuring fuel flow!
>
> Damn, there goes my opportunity...
>
> Actually you do't have to assume instant opening/closing: the
> opening/closing would be consistant so you'd only have to factor it
> into the equation. I think you'll find fuel pressure is also
> relatively constant too.
>
> I'll be this could be done on a laptop and a few hours of programming.
To get decent resolution, you'll actually want a small amount of
circuitry to do the interface - don't go hooking any wires straight to
your laptop!
If you want to pursue this, contact me. The email address is good.
I've done commercial and lab instrumrntation design for more years
than I like to remember so expect it to be over-engineered a bit to
begin with. I got to thinking about this last night and building a
safe interface for a laptop to give individual injector pulse with
plus a speed reference looks pretty simple. Hit a claibrate button at
some steady-state speed and then do a mpg computation relative to that
baseline.
--
Will Honea
> On Fri, 24 Feb 2006 07:16:33 GMT, "Will Honea" <[email protected]>
> wrote:
>
>
> >
> >A real quick and dirty would be to measure the injector pulse width.
> >Assuming instant opening, instant close and constant fuel pressure,
> >the fuel flow will be directly proportional to the on time.
> >Considerably less hassle and and a heck of a lot cheaper than directly
> >measuring fuel flow!
>
> Damn, there goes my opportunity...
>
> Actually you do't have to assume instant opening/closing: the
> opening/closing would be consistant so you'd only have to factor it
> into the equation. I think you'll find fuel pressure is also
> relatively constant too.
>
> I'll be this could be done on a laptop and a few hours of programming.
To get decent resolution, you'll actually want a small amount of
circuitry to do the interface - don't go hooking any wires straight to
your laptop!
If you want to pursue this, contact me. The email address is good.
I've done commercial and lab instrumrntation design for more years
than I like to remember so expect it to be over-engineered a bit to
begin with. I got to thinking about this last night and building a
safe interface for a laptop to give individual injector pulse with
plus a speed reference looks pretty simple. Hit a claibrate button at
some steady-state speed and then do a mpg computation relative to that
baseline.
--
Will Honea
P
PeterD
Guest
On Fri, 24 Feb 2006 18:05:05 GMT, "Will Honea" <[email protected]>
wrote:
>On Fri, 24 Feb 2006 14:05:23 UTC PeterD <[email protected]> wrote:
>
>To get decent resolution, you'll actually want a small amount of
>circuitry to do the interface - don't go hooking any wires straight to
>your laptop!
>
>If you want to pursue this, contact me. The email address is good.
>I've done commercial and lab instrumrntation design for more years
>than I like to remember so expect it to be over-engineered a bit to
>begin with. I got to thinking about this last night and building a
>safe interface for a laptop to give individual injector pulse with
>plus a speed reference looks pretty simple. Hit a claibrate button at
>some steady-state speed and then do a mpg computation relative to that
>baseline.
<g> My field too... I've the hardware, but most important thing is the
'disposable laptop' for when it breaks...
wrote:
>On Fri, 24 Feb 2006 14:05:23 UTC PeterD <[email protected]> wrote:
>
>To get decent resolution, you'll actually want a small amount of
>circuitry to do the interface - don't go hooking any wires straight to
>your laptop!
>
>If you want to pursue this, contact me. The email address is good.
>I've done commercial and lab instrumrntation design for more years
>than I like to remember so expect it to be over-engineered a bit to
>begin with. I got to thinking about this last night and building a
>safe interface for a laptop to give individual injector pulse with
>plus a speed reference looks pretty simple. Hit a claibrate button at
>some steady-state speed and then do a mpg computation relative to that
>baseline.
<g> My field too... I've the hardware, but most important thing is the
'disposable laptop' for when it breaks...
P
PeterD
Guest
On 24 Feb 2006 08:38:00 -0800, [email protected] wrote:
>
>PeterD wrote:
>
>
>> I hear they've got syncros on all gears *including* first now! Cool...
>> <bg>
>
>You know, I saw a car without a clutch pedal yesterday. And it did not
>have a control to retard the spark either (at least none that I could
>see sitting at the wheel).
VW, right? <g> their early 70s auto-stick shift. No clutch but did
have a shifter. Managed to get the worst of both worlds!
>
>PeterD wrote:
>
>
>> I hear they've got syncros on all gears *including* first now! Cool...
>> <bg>
>
>You know, I saw a car without a clutch pedal yesterday. And it did not
>have a control to retard the spark either (at least none that I could
>see sitting at the wheel).
VW, right? <g> their early 70s auto-stick shift. No clutch but did
have a shifter. Managed to get the worst of both worlds!
