Tyre question - slippery slope has begun
 

Hi All,

I have a very stock 2001 TJ 4.0L with automatic transmission and 3.07 diff
gearing with Dana 44 rear. The bug has finally bitten me and I am at a
stage where I need to change the tyres. Currently I am running 225/70R16
BF Goodrich All-Terrain T/A KOs on factory aluminium Icon 16x7inch rims.
After doing the last run on the track, it seems that I need ground
clearance, and fast. I have spent about a week researching what available
in the local market and what everybody else in the club is running and the
choice has come down to tyres.

1) Goodyear Wrangler MT/Rs - they are only available in two 16 sizes 235/85
(32 inch equivalent) and 255/70 (30 inch equivalent). I have read a lot of
good reviews about them in magazines, but nobody is running them in NZ.
They are expensive and hard to find. One of the dealers said, if you blow
a tyre it would be a week or two for a replacement to arrive. I do like
the look of it and the reviews in mags have been wonderful.

2) BF Goodrich Mud-Terrain T/A KM - they are available in various sizes and
everybody is running them here. They are also relatively cheaper to buy
and more commonly available. I am interested in three sizes 235/85 (32
inch), 265/75 (32 inch) and 255/85 (33 inch). I don't think I can go wider
than 265s on 7 inch rims. Also I don't really want to change the rims at
this stage.

The questions I have:

1) Any personal opinions on how the two tyres would perform in mud, wet
tracks and wet rocks (it rains a lot in NZ).

2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
stock TJ suspensions and without sway bars and have no rubbing at all at
any stage. I was thinking, can I perhaps then go with narrower 33s
(255/85R16) for now and upgrade the suspension in 3/4 months (which I can't
do rightnow due to the need for ------ing the budget a bit). I am new to
this sport, so don't do it every weekend. I can be careful during the
period while my suspension is stock.

3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.

4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
inch tyres. I am more inclined towards 33s as almost everybody else is
running at least 33s here and following those setups is not fun with my bum
rubbing on even pebbles in stock tyres.

Thanks all for your valuable input, you guys have been really helpful in
the past.

Cheers
TW

Re: Tyre question - slippery slope has begun
 

TW wrote:
> The questions I have:
>
> 1) Any personal opinions on how the two tyres would perform in mud, wet
> tracks and wet rocks (it rains a lot in NZ).

I drive similar terrain here in NS Canada on 33x10.50R15 BFG MTs. Work
very well. No complaints.

> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

First, I think you meant 33x11.50R15. Can't speak to the TJ, but with my
XJ, narrower tires let me get away with less lift. On stock wheels
though, you may find the tires rub on the inside wall of the wheel wells
when flexing. You will certainly have a reduced turning radius on road
or off due to rubbing on the lower control arms. Neither issue is likely
a show stopper. If you do try it, be sure the tires won't catch up on
any flares or exterior sheet metal. Maybe you could install some coil
spacers as a stop gap before you get your lift kit.

> 3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
> Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.

Likely intolerable with an auto trans. Nine months will seem like an
eternity, but you may be able to tough it out.

> 4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
> inch tyres. I am more inclined towards 33s as almost everybody else is
> running at least 33s here and following those setups is not fun with my bum
> rubbing on even pebbles in stock tyres.

With my BFG 33s (actual 32.8"), 4.10s and a 34 tooth gear, my speedo
clocks about 1 km/h faster than my GPS at 100 km/h. Pretty darn close.

> Thanks all for your valuable input, you guys have been really helpful in
> the past.

When I did my daily driver XJ last year, I too was in a twist over all
this stuff. I ended up doing lift, tires, and gears all in one pop. I
cheaped out on gears and got used D30/35 4.10s from one of the many
junked 4-cyls available locally. That got me up and running and I can
now take my time with wheels, bumpers, skids, lockers, winch, etc. I've
since built up a rear D44 with a Rubi air locker for little cash and no
time pressure.

Steve

Re: Tyre question - slippery slope has begun
 

TW wrote:
> The questions I have:
>
> 1) Any personal opinions on how the two tyres would perform in mud, wet
> tracks and wet rocks (it rains a lot in NZ).

I drive similar terrain here in NS Canada on 33x10.50R15 BFG MTs. Work
very well. No complaints.

> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

First, I think you meant 33x11.50R15. Can't speak to the TJ, but with my
XJ, narrower tires let me get away with less lift. On stock wheels
though, you may find the tires rub on the inside wall of the wheel wells
when flexing. You will certainly have a reduced turning radius on road
or off due to rubbing on the lower control arms. Neither issue is likely
a show stopper. If you do try it, be sure the tires won't catch up on
any flares or exterior sheet metal. Maybe you could install some coil
spacers as a stop gap before you get your lift kit.

> 3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
> Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.

Likely intolerable with an auto trans. Nine months will seem like an
eternity, but you may be able to tough it out.

> 4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
> inch tyres. I am more inclined towards 33s as almost everybody else is
> running at least 33s here and following those setups is not fun with my bum
> rubbing on even pebbles in stock tyres.

With my BFG 33s (actual 32.8"), 4.10s and a 34 tooth gear, my speedo
clocks about 1 km/h faster than my GPS at 100 km/h. Pretty darn close.

> Thanks all for your valuable input, you guys have been really helpful in
> the past.

When I did my daily driver XJ last year, I too was in a twist over all
this stuff. I ended up doing lift, tires, and gears all in one pop. I
cheaped out on gears and got used D30/35 4.10s from one of the many
junked 4-cyls available locally. That got me up and running and I can
now take my time with wheels, bumpers, skids, lockers, winch, etc. I've
since built up a rear D44 with a Rubi air locker for little cash and no
time pressure.

Steve

Re: Tyre question - slippery slope has begun
 

TW wrote:
> The questions I have:
>
> 1) Any personal opinions on how the two tyres would perform in mud, wet
> tracks and wet rocks (it rains a lot in NZ).

I drive similar terrain here in NS Canada on 33x10.50R15 BFG MTs. Work
very well. No complaints.

> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

First, I think you meant 33x11.50R15. Can't speak to the TJ, but with my
XJ, narrower tires let me get away with less lift. On stock wheels
though, you may find the tires rub on the inside wall of the wheel wells
when flexing. You will certainly have a reduced turning radius on road
or off due to rubbing on the lower control arms. Neither issue is likely
a show stopper. If you do try it, be sure the tires won't catch up on
any flares or exterior sheet metal. Maybe you could install some coil
spacers as a stop gap before you get your lift kit.

> 3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
> Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.

Likely intolerable with an auto trans. Nine months will seem like an
eternity, but you may be able to tough it out.

> 4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
> inch tyres. I am more inclined towards 33s as almost everybody else is
> running at least 33s here and following those setups is not fun with my bum
> rubbing on even pebbles in stock tyres.

With my BFG 33s (actual 32.8"), 4.10s and a 34 tooth gear, my speedo
clocks about 1 km/h faster than my GPS at 100 km/h. Pretty darn close.

> Thanks all for your valuable input, you guys have been really helpful in
> the past.

When I did my daily driver XJ last year, I too was in a twist over all
this stuff. I ended up doing lift, tires, and gears all in one pop. I
cheaped out on gears and got used D30/35 4.10s from one of the many
junked 4-cyls available locally. That got me up and running and I can
now take my time with wheels, bumpers, skids, lockers, winch, etc. I've
since built up a rear D44 with a Rubi air locker for little cash and no
time pressure.

Steve

Re: Tyre question - slippery slope has begun
 

TW wrote:
> The questions I have:
>
> 1) Any personal opinions on how the two tyres would perform in mud, wet
> tracks and wet rocks (it rains a lot in NZ).

I drive similar terrain here in NS Canada on 33x10.50R15 BFG MTs. Work
very well. No complaints.

> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

First, I think you meant 33x11.50R15. Can't speak to the TJ, but with my
XJ, narrower tires let me get away with less lift. On stock wheels
though, you may find the tires rub on the inside wall of the wheel wells
when flexing. You will certainly have a reduced turning radius on road
or off due to rubbing on the lower control arms. Neither issue is likely
a show stopper. If you do try it, be sure the tires won't catch up on
any flares or exterior sheet metal. Maybe you could install some coil
spacers as a stop gap before you get your lift kit.

> 3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
> Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.

Likely intolerable with an auto trans. Nine months will seem like an
eternity, but you may be able to tough it out.

> 4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
> inch tyres. I am more inclined towards 33s as almost everybody else is
> running at least 33s here and following those setups is not fun with my bum
> rubbing on even pebbles in stock tyres.

With my BFG 33s (actual 32.8"), 4.10s and a 34 tooth gear, my speedo
clocks about 1 km/h faster than my GPS at 100 km/h. Pretty darn close.

> Thanks all for your valuable input, you guys have been really helpful in
> the past.

When I did my daily driver XJ last year, I too was in a twist over all
this stuff. I ended up doing lift, tires, and gears all in one pop. I
cheaped out on gears and got used D30/35 4.10s from one of the many
junked 4-cyls available locally. That got me up and running and I can
now take my time with wheels, bumpers, skids, lockers, winch, etc. I've
since built up a rear D44 with a Rubi air locker for little cash and no
time pressure.

Steve

Re: Tyre question - slippery slope has begun
 

BFG don't do a 32 x 10.5 - its a 32 x 11.5. If they are running stock
suspension with no rubbing, I think you are mistaken and they are in fact
running 31 x 10.5

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"TW" <a t t w @ w a v e . c o . n z> wrote in message
news:c8cqgf$pqa$1@news.wave.co.nz...
> Hi All,
> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I
can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

Re: Tyre question - slippery slope has begun
 

BFG don't do a 32 x 10.5 - its a 32 x 11.5. If they are running stock
suspension with no rubbing, I think you are mistaken and they are in fact
running 31 x 10.5

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"TW" <a t t w @ w a v e . c o . n z> wrote in message
news:c8cqgf$pqa$1@news.wave.co.nz...
> Hi All,
> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I
can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

Re: Tyre question - slippery slope has begun
 

BFG don't do a 32 x 10.5 - its a 32 x 11.5. If they are running stock
suspension with no rubbing, I think you are mistaken and they are in fact
running 31 x 10.5

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"TW" <a t t w @ w a v e . c o . n z> wrote in message
news:c8cqgf$pqa$1@news.wave.co.nz...
> Hi All,
> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I
can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

Re: Tyre question - slippery slope has begun
 

BFG don't do a 32 x 10.5 - its a 32 x 11.5. If they are running stock
suspension with no rubbing, I think you are mistaken and they are in fact
running 31 x 10.5

Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"TW" <a t t w @ w a v e . c o . n z> wrote in message
news:c8cqgf$pqa$1@news.wave.co.nz...
> Hi All,
> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I
can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.

Re: Tyre question - slippery slope has begun
 

"TW" <a t t w @ w a v e . c o . n z> wrote in message
news:c8cqgf$pqa$1@news.wave.co.nz...
> Hi All,
>
> I have a very stock 2001 TJ 4.0L with automatic transmission and 3.07 diff
> gearing with Dana 44 rear. The bug has finally bitten me and I am at a
> stage where I need to change the tyres. Currently I am running 225/70R16
> BF Goodrich All-Terrain T/A KOs on factory aluminium Icon 16x7inch rims.
> After doing the last run on the track, it seems that I need ground
> clearance, and fast. I have spent about a week researching what available
> in the local market and what everybody else in the club is running and the
> choice has come down to tyres.
>
> 1) Goodyear Wrangler MT/Rs - they are only available in two 16 sizes
235/85
> (32 inch equivalent) and 255/70 (30 inch equivalent). I have read a lot
of
> good reviews about them in magazines, but nobody is running them in NZ.
> They are expensive and hard to find. One of the dealers said, if you blow
> a tyre it would be a week or two for a replacement to arrive. I do like
> the look of it and the reviews in mags have been wonderful.
>
> 2) BF Goodrich Mud-Terrain T/A KM - they are available in various sizes
and
> everybody is running them here. They are also relatively cheaper to buy
> and more commonly available. I am interested in three sizes 235/85 (32
> inch), 265/75 (32 inch) and 255/85 (33 inch). I don't think I can go
wider
> than 265s on 7 inch rims. Also I don't really want to change the rims at
> this stage.
>
> The questions I have:
>
> 1) Any personal opinions on how the two tyres would perform in mud, wet
> tracks and wet rocks (it rains a lot in NZ).
>
> 2) Two guys in our club are running 32/10.5 R15 BF Goodrich Mud-Terrain on
> stock TJ suspensions and without sway bars and have no rubbing at all at
> any stage. I was thinking, can I perhaps then go with narrower 33s
> (255/85R16) for now and upgrade the suspension in 3/4 months (which I
can't
> do rightnow due to the need for ------ing the budget a bit). I am new to
> this sport, so don't do it every weekend. I can be careful during the
> period while my suspension is stock.
>
> 3) How much of a power loss would it be due to 3.07 gearing. Its an auto.
> Regearing to 4.10 or 4.56 is in the plans, but more like 9/12 months away.
>
> 4) Which speedo gear would I need to recalibrate my speedo with 32 or 33
> inch tyres. I am more inclined towards 33s as almost everybody else is
> running at least 33s here and following those setups is not fun with my
bum
> rubbing on even pebbles in stock tyres.
>
> Thanks all for your valuable input, you guys have been really helpful in
> the past.
>
> Cheers
> TW
>

Well, the Mud Terrains are the way to go. I was going to suggest you
consider the All Terrains, they actually are a better all around tire for
dry conditions, but you said the conditions at your house are seldom dry, so
the MTs will work better. The ATs fill with mud whereas the MTs will clean
themselves, theoretically.

I think the max you can put under a TJ without lift is a 31. I think that
the size that will work best for you will be a 32, max. I know several guys
with larger tires than I have (I have the BFG Mud Terrain in a 32 x 11.50) -
BTW, can you get tires in the "inch sizes", 32 x 11.50, 31 x 10.50, etc.? -
and they can't do much more than I can do.

You are going to run into gearing issues soon no matter which size you
choose, but since you have the automatic trans, you might not notice. All
things considered, gearing and lack of lift, I think you will be best with
the 31" tire options. You can put any available width (in a 31, and most
widths in a 32) on the standard rims.