CJ I6 question
Guest
Posts: n/a
Re: CJ I6 question
I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
Guest
Posts: n/a
Re: CJ I6 question
I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
Guest
Posts: n/a
Re: CJ I6 question
I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
equivalent for the bigger off road sizes that I know) and at 65 mph in
4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
drops radically as well.
That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
best mileage (23 mpg) and tons of punch if needed. It will hold it up
any highway hill I have hit.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Clap Trap wrote:
>
> For someone with a stock CJ using the 4.2l I-6 with the T-5 tranny and
> stock tires...
>
> What is the engine RPM at any speed (say 55 MPH) in 4th? In 5th?
>
> What size, actually, are the stock tires? (In metric values please -
> ie, p215 75R25 etc).
>
> Thanks
Guest
Posts: n/a
Re: CJ I6 question
Mike Romain wrote:
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
Guest
Posts: n/a
Re: CJ I6 question
Mike Romain wrote:
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
Guest
Posts: n/a
Re: CJ I6 question
Mike Romain wrote:
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> equivalent for the bigger off road sizes that I know) and at 65 mph in
> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> drops radically as well.
>
> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> best mileage (23 mpg) and tons of punch if needed. It will hold it up
> any highway hill I have hit.
>
Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
gears. Mine runs about the same as yours. But, mileage stinks in
either. RPMs in 4th are too high, 5th too low. I am getting ready for
another round of upgrades and was thinking about regearing the axles
since I really don't need bigger tires or a lift.
Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
Guest
Posts: n/a
Re: CJ I6 question
Clap Trap wrote:
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Guest
Posts: n/a
Re: CJ I6 question
Clap Trap wrote:
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Guest
Posts: n/a
Re: CJ I6 question
Clap Trap wrote:
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
>
> Mike Romain wrote:
> > I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
> > equivalent for the bigger off road sizes that I know) and at 65 mph in
> > 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
> > drops radically as well.
> >
> > That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
> > best mileage (23 mpg) and tons of punch if needed. It will hold it up
> > any highway hill I have hit.
> >
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
The CJ7 came with 31's for some versions and 31's fit any stock one like
the TJ so you are 'really' close.
I get a sweet 23 mpg on the highway fully loaded running at 65 mph. If
I run at 75-80 I drop to 18 or 19 mpg, if I run at 50-55 on secondary
roads I get 25+ mpg. I have a 200 mile regular route to check it on.
I don't use 5th.
I was told the engine has the advance full around 2300 and I run an
Accel SuperCoil for a hot spark with the engine set up manually. I
killed the computer.
When I killed the computer, my top end went from a 3500 rpm bog to a
fast 4400 rpm which will pull me quick up to 50 mph in 2nd gear!!!!
My friends and they are folks from the group say they got 10 mph per
gear with the computer sleeping.
I also went up 100 miles per tank for gas mileage when I use 92 octane.
I still pass emissions and so do a bunch of friends who have also killed
the computers.
Manually the 258 can be tuned up to run sweet and just purr at idle,
though a bit of a lean rumble at idle is better for the emissions
sniffer.
Here is a link the the best boost you can give it and it is free!
http://home.sprynet.com/~dale02/ignmods.htm
I add two new wires rather than mess in the harness like the author
does.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Guest
Posts: n/a
Re: CJ I6 question
Factory gearing was typically the 3.07 axle ratio which will give you
about 1700 rpm at 60 mph in 5th. A real DOG!!!!
I'm with Mike, around 2300 is a good spot on the 258 engine. The 4
banger runs best around 2800 to 3000.
Clap Trap wrote:
> Mike Romain wrote:
>
>> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
>> equivalent for the bigger off road sizes that I know) and at 65 mph in
>> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
>> drops radically as well.
>> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
>> best mileage (23 mpg) and tons of punch if needed. It will hold it up
>> any highway hill I have hit.
>>
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
>
about 1700 rpm at 60 mph in 5th. A real DOG!!!!
I'm with Mike, around 2300 is a good spot on the 258 engine. The 4
banger runs best around 2800 to 3000.
Clap Trap wrote:
> Mike Romain wrote:
>
>> I have a 258, T-5 with 3.31 gears turning 33x9.5" BFG muds (no metric
>> equivalent for the bigger off road sizes that I know) and at 65 mph in
>> 4th I spin 2300 rpm. If I use 5th it drops to 1750 and my gas mileage
>> drops radically as well.
>> That 2300 rpm seems to be a nice 'sweet spot' for my engine with the
>> best mileage (23 mpg) and tons of punch if needed. It will hold it up
>> any highway hill I have hit.
>>
>
> Thanks Mike. Mine has the 258, T-5, and 31x10.50s on it, also with 3.31
> gears. Mine runs about the same as yours. But, mileage stinks in
> either. RPMs in 4th are too high, 5th too low. I am getting ready for
> another round of upgrades and was thinking about regearing the axles
> since I really don't need bigger tires or a lift.
>
> Any idea what the factory RPM was supposed to be in 5th at 55 or 60?
>
