Coasty

That is why I asked the question it makes sense. Also, it was an SE TJ I
looked at it yesterday. He is a young kid at work and his dad gave him the
TJ because his car died. It gave his dad a new excuse to get a Rubicon. He
see me with my TJ and has a ton of questions I told him I do not know some
of the answers but I know where to ask.

--
Coasty
SEMPAR PARATUS
(ALWAYS READY)

Remove The SPOOGE To Reply
"L.W. ("ßill") ------ III" <----------@***.net> wrote in message
news:42C83FE5.65D697E1@***.net...
> Before the 31"s my Brother-in-law's '94 YJ four banger could go any
> speed he wanted on the straight and level, and got a ticket for ninety,
> after the extra weight limited that to seventy miles per hour and that's
> with a tailwind: http://home.att.net/~taschers/beach03.jpg
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> Coasty wrote:
>>
>> Yep another one,
>> A friend has a 2.5L TJ X, 5 speed tranny,with standard OEM tires
>> 215/75R-15,
>> he wants to put 31s on it. His question to me how bad will his mileage
>> suffer? He averages about 17-18 MPG now with gas the way it is he uses
>> the
>> TJ as the daily driver and drives 120 miles round trip to work each day.
>>
>> --
>> Coasty
>> SEMPAR PARATUS
>> (ALWAYS READY)
>>
>> Remove The SPOOGE To Reply

Old Crow

Greg wrote:
> Daughter's 95 YJ with 2.5 sucked on gas stock, sucked on gas with 31"s,
> and still sucks on gas with 33"s and 4.88s.
>

My '95 YJ with the 4 cyl. Had 30x9.50's on it and now has 235-70's.
On a measured 135 mile round trip commute it averages 20 mpg...with
either tire on it. Just has a bit more pick up with the 235's

My wife's '94 YJ with a 6 cyl. Had 215-70's on it when we got it. Now
has 30x 9.50's. On the same 135 mile commmute, it also averages around
20 mpg.

The only way tire size seems to have affected the gas mileage was by
the change in the speedo reading. Over an actual measured course, not
using the odometer as a reference, the mileage didn't hardly change.

--
Old Crow
'82 FLTC-P "Pearl"
'95 Jeep YJ Rio Grande
SENS, TOMKAT, BS#133, DOF#51, MAMBM
"There's only *one* RE"

Old Crow

Greg wrote:
> Daughter's 95 YJ with 2.5 sucked on gas stock, sucked on gas with 31"s,
> and still sucks on gas with 33"s and 4.88s.
>

My '95 YJ with the 4 cyl. Had 30x9.50's on it and now has 235-70's.
On a measured 135 mile round trip commute it averages 20 mpg...with
either tire on it. Just has a bit more pick up with the 235's

My wife's '94 YJ with a 6 cyl. Had 215-70's on it when we got it. Now
has 30x 9.50's. On the same 135 mile commmute, it also averages around
20 mpg.

The only way tire size seems to have affected the gas mileage was by
the change in the speedo reading. Over an actual measured course, not
using the odometer as a reference, the mileage didn't hardly change.

--
Old Crow
'82 FLTC-P "Pearl"
'95 Jeep YJ Rio Grande
SENS, TOMKAT, BS#133, DOF#51, MAMBM
"There's only *one* RE"

Old Crow

Greg wrote:
> Daughter's 95 YJ with 2.5 sucked on gas stock, sucked on gas with 31"s,
> and still sucks on gas with 33"s and 4.88s.
>

My '95 YJ with the 4 cyl. Had 30x9.50's on it and now has 235-70's.
On a measured 135 mile round trip commute it averages 20 mpg...with
either tire on it. Just has a bit more pick up with the 235's

My wife's '94 YJ with a 6 cyl. Had 215-70's on it when we got it. Now
has 30x 9.50's. On the same 135 mile commmute, it also averages around
20 mpg.

The only way tire size seems to have affected the gas mileage was by
the change in the speedo reading. Over an actual measured course, not
using the odometer as a reference, the mileage didn't hardly change.

--
Old Crow
'82 FLTC-P "Pearl"
'95 Jeep YJ Rio Grande
SENS, TOMKAT, BS#133, DOF#51, MAMBM
"There's only *one* RE"

Old Crow

Greg wrote:
> Daughter's 95 YJ with 2.5 sucked on gas stock, sucked on gas with 31"s,
> and still sucks on gas with 33"s and 4.88s.
>

My '95 YJ with the 4 cyl. Had 30x9.50's on it and now has 235-70's.
On a measured 135 mile round trip commute it averages 20 mpg...with
either tire on it. Just has a bit more pick up with the 235's

My wife's '94 YJ with a 6 cyl. Had 215-70's on it when we got it. Now
has 30x 9.50's. On the same 135 mile commmute, it also averages around
20 mpg.

The only way tire size seems to have affected the gas mileage was by
the change in the speedo reading. Over an actual measured course, not
using the odometer as a reference, the mileage didn't hardly change.

--
Old Crow
'82 FLTC-P "Pearl"
'95 Jeep YJ Rio Grande
SENS, TOMKAT, BS#133, DOF#51, MAMBM
"There's only *one* RE"

Earle Horton

Bill,

E=mc² is not a formula from classical mechanics, which is what you are
talking about here. The energy to get a wheel, or any other object,
spinning depends on its "inertial mass", which is usually called "moment of
inertia", and the effective radius. Calculus gives the formula E=1/2 IR²,
which is similar to the formula for a moving object, E=1/2 mv², where m is
the mass of the object and v is the velocity.

Now, once you get an object moving or spinning, there is NO energy required
to keep it doing that, unless there are losses. In a vehicle, losses are
friction, air resistance, and that hundred pound girlfriend's credit card
usage. The wheels on Lance's bike have to be light because of the need to
accelerate, decelerate, and turn. Big heavy mountain bike wheels would slow
him down, but not for the reasons you state.

Earle

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:42C8CF21.A4377FAB@***.net...
> Horsepower, or imagine the the force you would need to peddle your
> bicycle, now put your Jeep tire on the bicycle and peddle. E=mc². The E
> stands for energy. The m stands for inertial mass, which is similar to
> (but not the same thing as) weight. C squared stands for the speed of
> light multiplied by itself. I would say Lance Armstrong bike wheel are
> very light right about now in france, not like his mountain bike.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RoyJ wrote:
> >
> > The reason you use a 13 pound flywheel is to allow maximum ACCELERATION
> > of the engine. The reason for lightweight tires is to allow
> > ACCELERATION. The reason to not take your girlfriend along is
> > ACCELERATION So what does weight have to do with steady state? (other
> > than the additional wear on the bearings?)
> >
> > L.W.(ßill) ------ III wrote:
> >
> > > Hi Dave,
> > > To keep something turning takes more horsepower the heavier it
is,
> > > that's why the drag racers use a thirteen pound aluminum flywheel and
> > > lighter rims and tires. Of course, that flywheel also stores energy,
> > > that will made the stock V6 buick power CJ with it's fifty pound
> > > flywheel easily crawl over rocks that would easily stop a couple of
> > > hundred more horsepower in a 350" Chevy V8. I know taking your hundred
> > > pound girlfriend with you down the drag strip will cost you a tenth of
a
> > > second. As far as sprung and unsprung weight, all I know is it makes a
> > > great deal of difference in their ride and cornering ability, like
road
> > > racers need independent suspension to win.
> > > God Bless America, ßill O|||||||O
> > > mailto:-------------------- http://www.----------.com/
> > >
> > > Dave Milne wrote:
> > >
> > >>I read somewhere that every lb of unsprung weight is worth 10 lb of
sprung
> > >>weight ; don't know if that's true or not.
> > >>
> > >>Dave Milne, Scotland
> > >>'91 Grand Wagoneer, '99 TJ

Earle Horton

Bill,

E=mc² is not a formula from classical mechanics, which is what you are
talking about here. The energy to get a wheel, or any other object,
spinning depends on its "inertial mass", which is usually called "moment of
inertia", and the effective radius. Calculus gives the formula E=1/2 IR²,
which is similar to the formula for a moving object, E=1/2 mv², where m is
the mass of the object and v is the velocity.

Now, once you get an object moving or spinning, there is NO energy required
to keep it doing that, unless there are losses. In a vehicle, losses are
friction, air resistance, and that hundred pound girlfriend's credit card
usage. The wheels on Lance's bike have to be light because of the need to
accelerate, decelerate, and turn. Big heavy mountain bike wheels would slow
him down, but not for the reasons you state.

Earle

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:42C8CF21.A4377FAB@***.net...
> Horsepower, or imagine the the force you would need to peddle your
> bicycle, now put your Jeep tire on the bicycle and peddle. E=mc². The E
> stands for energy. The m stands for inertial mass, which is similar to
> (but not the same thing as) weight. C squared stands for the speed of
> light multiplied by itself. I would say Lance Armstrong bike wheel are
> very light right about now in france, not like his mountain bike.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RoyJ wrote:
> >
> > The reason you use a 13 pound flywheel is to allow maximum ACCELERATION
> > of the engine. The reason for lightweight tires is to allow
> > ACCELERATION. The reason to not take your girlfriend along is
> > ACCELERATION So what does weight have to do with steady state? (other
> > than the additional wear on the bearings?)
> >
> > L.W.(ßill) ------ III wrote:
> >
> > > Hi Dave,
> > > To keep something turning takes more horsepower the heavier it
is,
> > > that's why the drag racers use a thirteen pound aluminum flywheel and
> > > lighter rims and tires. Of course, that flywheel also stores energy,
> > > that will made the stock V6 buick power CJ with it's fifty pound
> > > flywheel easily crawl over rocks that would easily stop a couple of
> > > hundred more horsepower in a 350" Chevy V8. I know taking your hundred
> > > pound girlfriend with you down the drag strip will cost you a tenth of
a
> > > second. As far as sprung and unsprung weight, all I know is it makes a
> > > great deal of difference in their ride and cornering ability, like
road
> > > racers need independent suspension to win.
> > > God Bless America, ßill O|||||||O
> > > mailto:-------------------- http://www.----------.com/
> > >
> > > Dave Milne wrote:
> > >
> > >>I read somewhere that every lb of unsprung weight is worth 10 lb of
sprung
> > >>weight ; don't know if that's true or not.
> > >>
> > >>Dave Milne, Scotland
> > >>'91 Grand Wagoneer, '99 TJ

Earle Horton

Bill,

E=mc² is not a formula from classical mechanics, which is what you are
talking about here. The energy to get a wheel, or any other object,
spinning depends on its "inertial mass", which is usually called "moment of
inertia", and the effective radius. Calculus gives the formula E=1/2 IR²,
which is similar to the formula for a moving object, E=1/2 mv², where m is
the mass of the object and v is the velocity.

Now, once you get an object moving or spinning, there is NO energy required
to keep it doing that, unless there are losses. In a vehicle, losses are
friction, air resistance, and that hundred pound girlfriend's credit card
usage. The wheels on Lance's bike have to be light because of the need to
accelerate, decelerate, and turn. Big heavy mountain bike wheels would slow
him down, but not for the reasons you state.

Earle

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:42C8CF21.A4377FAB@***.net...
> Horsepower, or imagine the the force you would need to peddle your
> bicycle, now put your Jeep tire on the bicycle and peddle. E=mc². The E
> stands for energy. The m stands for inertial mass, which is similar to
> (but not the same thing as) weight. C squared stands for the speed of
> light multiplied by itself. I would say Lance Armstrong bike wheel are
> very light right about now in france, not like his mountain bike.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RoyJ wrote:
> >
> > The reason you use a 13 pound flywheel is to allow maximum ACCELERATION
> > of the engine. The reason for lightweight tires is to allow
> > ACCELERATION. The reason to not take your girlfriend along is
> > ACCELERATION So what does weight have to do with steady state? (other
> > than the additional wear on the bearings?)
> >
> > L.W.(ßill) ------ III wrote:
> >
> > > Hi Dave,
> > > To keep something turning takes more horsepower the heavier it
is,
> > > that's why the drag racers use a thirteen pound aluminum flywheel and
> > > lighter rims and tires. Of course, that flywheel also stores energy,
> > > that will made the stock V6 buick power CJ with it's fifty pound
> > > flywheel easily crawl over rocks that would easily stop a couple of
> > > hundred more horsepower in a 350" Chevy V8. I know taking your hundred
> > > pound girlfriend with you down the drag strip will cost you a tenth of
a
> > > second. As far as sprung and unsprung weight, all I know is it makes a
> > > great deal of difference in their ride and cornering ability, like
road
> > > racers need independent suspension to win.
> > > God Bless America, ßill O|||||||O
> > > mailto:-------------------- http://www.----------.com/
> > >
> > > Dave Milne wrote:
> > >
> > >>I read somewhere that every lb of unsprung weight is worth 10 lb of
sprung
> > >>weight ; don't know if that's true or not.
> > >>
> > >>Dave Milne, Scotland
> > >>'91 Grand Wagoneer, '99 TJ

Earle Horton

Bill,

E=mc² is not a formula from classical mechanics, which is what you are
talking about here. The energy to get a wheel, or any other object,
spinning depends on its "inertial mass", which is usually called "moment of
inertia", and the effective radius. Calculus gives the formula E=1/2 IR²,
which is similar to the formula for a moving object, E=1/2 mv², where m is
the mass of the object and v is the velocity.

Now, once you get an object moving or spinning, there is NO energy required
to keep it doing that, unless there are losses. In a vehicle, losses are
friction, air resistance, and that hundred pound girlfriend's credit card
usage. The wheels on Lance's bike have to be light because of the need to
accelerate, decelerate, and turn. Big heavy mountain bike wheels would slow
him down, but not for the reasons you state.

Earle

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:42C8CF21.A4377FAB@***.net...
> Horsepower, or imagine the the force you would need to peddle your
> bicycle, now put your Jeep tire on the bicycle and peddle. E=mc². The E
> stands for energy. The m stands for inertial mass, which is similar to
> (but not the same thing as) weight. C squared stands for the speed of
> light multiplied by itself. I would say Lance Armstrong bike wheel are
> very light right about now in france, not like his mountain bike.
> God Bless America, ßill O|||||||O
> mailto:-------------------- http://www.----------.com/
>
> RoyJ wrote:
> >
> > The reason you use a 13 pound flywheel is to allow maximum ACCELERATION
> > of the engine. The reason for lightweight tires is to allow
> > ACCELERATION. The reason to not take your girlfriend along is
> > ACCELERATION So what does weight have to do with steady state? (other
> > than the additional wear on the bearings?)
> >
> > L.W.(ßill) ------ III wrote:
> >
> > > Hi Dave,
> > > To keep something turning takes more horsepower the heavier it
is,
> > > that's why the drag racers use a thirteen pound aluminum flywheel and
> > > lighter rims and tires. Of course, that flywheel also stores energy,
> > > that will made the stock V6 buick power CJ with it's fifty pound
> > > flywheel easily crawl over rocks that would easily stop a couple of
> > > hundred more horsepower in a 350" Chevy V8. I know taking your hundred
> > > pound girlfriend with you down the drag strip will cost you a tenth of
a
> > > second. As far as sprung and unsprung weight, all I know is it makes a
> > > great deal of difference in their ride and cornering ability, like
road
> > > racers need independent suspension to win.
> > > God Bless America, ßill O|||||||O
> > > mailto:-------------------- http://www.----------.com/
> > >
> > > Dave Milne wrote:
> > >
> > >>I read somewhere that every lb of unsprung weight is worth 10 lb of
sprung
> > >>weight ; don't know if that's true or not.
> > >>
> > >>Dave Milne, Scotland
> > >>'91 Grand Wagoneer, '99 TJ

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

Hi Earle,
Yes, I know that's why I wrote the definition of C squared as the
speed of light.
Lance, will happy to know you have the secret of spontaneous energy
in that your wheel will never stop spinning. Size means nothing to you,
if you had a big enough lever you could move the earth. Where the rest
of us have to deal with centrifugal, kinetic, and inertia.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Earle Horton wrote:
>
> Bill,
>
> E=mc² is not a formula from classical mechanics, which is what you are
> talking about here. The energy to get a wheel, or any other object,
> spinning depends on its "inertial mass", which is usually called "moment of
> inertia", and the effective radius. Calculus gives the formula E=1/2 IR²,
> which is similar to the formula for a moving object, E=1/2 mv², where m is
> the mass of the object and v is the velocity.
>
> Now, once you get an object moving or spinning, there is NO energy required
> to keep it doing that, unless there are losses. In a vehicle, losses are
> friction, air resistance, and that hundred pound girlfriend's credit card
> usage. The wheels on Lance's bike have to be light because of the need to
> accelerate, decelerate, and turn. Big heavy mountain bike wheels would slow
> him down, but not for the reasons you state.
>
> Earle
>
> "L.W. (ßill) ------ III" <----------@***.net> wrote in message
> news:42C8CF21.A4377FAB@***.net...
> > Horsepower, or imagine the the force you would need to peddle your
> > bicycle, now put your Jeep tire on the bicycle and peddle. E=mc². The E
> > stands for energy. The m stands for inertial mass, which is similar to
> > (but not the same thing as) weight. C squared stands for the speed of
> > light multiplied by itself. I would say Lance Armstrong bike wheel are
> > very light right about now in france, not like his mountain bike.
> > God Bless America, ßill O|||||||O
> > mailto:-------------------- http://www.----------.com/
> >
> > RoyJ wrote:
> > >
> > > The reason you use a 13 pound flywheel is to allow maximum ACCELERATION
> > > of the engine. The reason for lightweight tires is to allow
> > > ACCELERATION. The reason to not take your girlfriend along is
> > > ACCELERATION So what does weight have to do with steady state? (other
> > > than the additional wear on the bearings?)
> > >
> > > L.W.(ßill) ------ III wrote:
> > >
> > > > Hi Dave,
> > > > To keep something turning takes more horsepower the heavier it
> is,
> > > > that's why the drag racers use a thirteen pound aluminum flywheel and
> > > > lighter rims and tires. Of course, that flywheel also stores energy,
> > > > that will made the stock V6 buick power CJ with it's fifty pound
> > > > flywheel easily crawl over rocks that would easily stop a couple of
> > > > hundred more horsepower in a 350" Chevy V8. I know taking your hundred
> > > > pound girlfriend with you down the drag strip will cost you a tenth of
> a
> > > > second. As far as sprung and unsprung weight, all I know is it makes a
> > > > great deal of difference in their ride and cornering ability, like
> road
> > > > racers need independent suspension to win.
> > > > God Bless America, ßill O|||||||O
> > > > mailto:-------------------- http://www.----------.com/
> > > >
> > > > Dave Milne wrote:
> > > >
> > > >>I read somewhere that every lb of unsprung weight is worth 10 lb of
> sprung
> > > >>weight ; don't know if that's true or not.
> > > >>
> > > >>Dave Milne, Scotland
> > > >>'91 Grand Wagoneer, '99 TJ