From owner-xj-digest-at-digest.net Wed Apr 11 21:25:45 2007 From: xj-digest xj-digest Thursday, April 12 2007 Volume 01 : Number 2552 Forum for Discussion of XJ cherokees and wagoneers Brian Colucci Digest Coordinator Contents: Re: xj: full tim(e) 4wd in JGC Re: xj: full tim(e) 4wd in JGC Re: xj: full tim 4wd in JGC Re: xj: full tim 4wd in JGC Re: xj: full tim(e) 4wd in JGC Re: xj: full tim(e) 4wd in JGC XJ Digest Home Page: http://www.digest.net/jeep/xj/ Send submissions to xj-digest-at-digest.net Send administrative requests to xj-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to xj-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: Wed, 11 Apr 2007 15:18:30 -0700 From: ernest breakfield Subject: Re: xj: full tim(e) 4wd in JGC hi ed! you didn't mention which motors, gearing or trannys your J**ps have, but for the sake of discussion i'll ASSuME they have the same gear ratios and *guess* they're both likely 4.0s with automatics. firstly, the AW4 in most XJs is almost always going to outperform the sloppier ChryCo auto tranny in (most of) the ZJs. you also didn't mention what kind and sizes of tires they both have, and that can make a big difference. (i'm going to go out on a limb and ASSuME you've already checked to make sure the tire pressures are all even and correct... or all bets are off.) you also didn't mention what kind of driving she's doing; and "passive and careful" isn't necessarily efficient if she's using the brakes a lot to scrub off speed she just accelerated to get instead of allowing the vehicle to coast. if you're "rarely under 75", you're doing a good percentage of your time at highway speeds where the torque converter is always locked up and most efficient. if she's doing most of her mileage around town with constant starts from a dead stop in the heavier vehicle, her mileage is never going to be great. (if all other factors were equal, the ZJ should have a slight advantage on the hwy, as its body style has a lower C.D.) to be totally fair, you'd both have to switch vehicles for a few tanks to see how they played out, and determine how much of the difference between the 2 is the vehicle vs driving style and usage. also, it's likely that your XJ has the ill-fated front axle disconnect that disconnects the front axle from the driveline, removing a tiny percentage of drag (assuming that it's still working properly). as an aside, i wouldn't pay any attention to any trip computer; it's good for entertainment value at best. figuring your (her) actual fuel consumption by resetting the trip odometer to Zero at a fill-up. record how much mileage is on it again at the next fillup, and divide the number of gallons by the actual miles reported travelled; you may be surprised at the percentage of variance... but i doubt you're ever going to see a 3-5 MPG increase in identical use. you can make sure you've got all the regualr service items in good shape (like making sure the air cleaner is clean), but the cost of changing out major components to try to achieve an increase in fuel efficiency isn't likely to be cost-justified in the lifetime of the vehicle. the sad reality is, if fuel consumption is a concern, unless she has a legitimate need for a high-clearance 4WD station wagon, she's driving the wrong vehicle. cheers! e Ed Kummel wrote: > So, my wife drives a '96 JGC Limited and loves the thing. > But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. > Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. > So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? > I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. > Thanks > Ed ------------------------------ Date: Wed, 11 Apr 2007 20:09:13 -0500 From: "Allen Zylstra" Subject: Re: xj: full tim(e) 4wd in JGC I also have a 96 JGC 4.0 auto with part-time 4x4. I average about 15-16 in suburbia driving. 17-18 highway. Now with the 31s that has dropped about .5 mpg. I wanted a XJ to drive, but the 34mpg of my new beater escort wagon is hard to beat. I save about $40 a week in gas with it and the ZJ stays home most of the time. Allen -------------------------------------------------------------------- From: ernest breakfield Reply-To: xj-at-digest.net To: xj-at-digest.net Subject: Re: xj: full tim(e) 4wd in JGC Date: Wed, 11 Apr 2007 15:18:30 -0700 >hi ed! > > you didn't mention which motors, gearing or trannys your J**ps have, >but for the sake of discussion i'll ASSuME they have the same gear >ratios and *guess* they're both likely 4.0s with automatics. > > firstly, the AW4 in most XJs is almost always going to outperform >the sloppier ChryCo auto tranny in (most of) the ZJs. > > you also didn't mention what kind and sizes of tires they both have, >and that can make a big difference. (i'm going to go out on a limb and >ASSuME you've already checked to make sure the tire pressures are all >even and correct... or all bets are off.) > > you also didn't mention what kind of driving she's doing; and >"passive and careful" isn't necessarily efficient if she's using the >brakes a lot to scrub off speed she just accelerated to get instead of >allowing the vehicle to coast. > if you're "rarely under 75", you're doing a good percentage of your >time at highway speeds where the torque converter is always locked up >and most efficient. if she's doing most of her mileage around town with >constant starts from a dead stop in the heavier vehicle, her mileage is >never going to be great. (if all other factors were equal, the ZJ should >have a slight advantage on the hwy, as its body style has a lower C.D.) > to be totally fair, you'd both have to switch vehicles for a few >tanks to see how they played out, and determine how much of the >difference between the 2 is the vehicle vs driving style and usage. > > also, it's likely that your XJ has the ill-fated front axle >disconnect that disconnects the front axle from the driveline, removing >a tiny percentage of drag (assuming that it's still working properly). > > as an aside, i wouldn't pay any attention to any trip computer; it's >good for entertainment value at best. > figuring your (her) actual fuel consumption by resetting the trip >odometer to Zero at a fill-up. record how much mileage is on it again at >the next fillup, and divide the number of gallons by the actual miles >reported travelled; you may be surprised at the percentage of >variance... but i doubt you're ever going to see a 3-5 MPG increase in >identical use. > > you can make sure you've got all the regualr service items in good >shape (like making sure the air cleaner is clean), but the cost of >changing out major components to try to achieve an increase in fuel >efficiency isn't likely to be cost-justified in the lifetime of the vehicle. > the sad reality is, if fuel consumption is a concern, unless she has >a legitimate need for a high-clearance 4WD station wagon, she's driving >the wrong vehicle. > > >cheers! >e > > >Ed Kummel wrote: > > So, my wife drives a '96 JGC Limited and loves the thing. > > But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. > > Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. > > So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? > > I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. > > Thanks > > Ed today. ------------------------------ Date: Wed, 11 Apr 2007 18:57:03 -0700 (PDT) From: john Subject: Re: xj: full tim 4wd in JGC problem is the trans in the zj.. it's a 42re, 3 speed... swap in an aw4 and you'd be happy... xfr case will make little differencw, if any... have run mine in bith pt abd ft and it's about the same sending this from my treo in SD... sorry for the typos... btw, actually saw a rusted xj today! minnesota plates... john On Wed, 11 Apr 2007, Ed Kummel wrote: >-->So, my wife drives a '96 JGC Limited and loves the thing. >--> But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. >--> Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. >--> So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? >--> I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. >--> Thanks >--> Ed >--> web/gadget guru >--> >--> >-->------------------------------------------------------------------------ >-->"The rule in Silicon Valley is that if Apple leaves the table smiling, the other guy got screwed," >--> - Rob Enderle, independant analyst on the Apple/Cisco iPhone lawsuit >--> >-->--------------------------------- >-->We won't tell. Get more on shows you hate to love >-->(and love to hate): Yahoo! TV's Guilty Pleasures list. >--> ----- - ---------------------------------------------------------------------- Snohomish, Washington -o|||||o- where Jeeps don't rust, they mold http://freegift.com ** http://wagoneers.com ** - ---------------------------------------------------------------------- ------------------------------ Date: Wed, 11 Apr 2007 20:44:06 -0700 From: "Jim Blair" Subject: Re: xj: full tim 4wd in JGC A: What makes the difference is a combination of things. First, the auto trans sucks. It's a Mopar auto with high stall and a big deficiency in the fuel economy dept. (mostly pumping losses) Those who are lucky enough to have a '93 with the AW4 will attest the power difference is noticeable from the Mopar to the AW trans. Fuel economy rating was also dropped with the Mopar trans compared to the AW4 in the same rig. The AWD doesn't make that huge a difference, but it may do 1-3 mpg. I add BG's 44K to clean my injectors and clean all the vacuum lines, etc to ensure it's operating correctly. Gear ratios and tire sizes account for a lot of stuff too. I'm looking forward to LPG in mine at $1.55 a gallon. From: Ed Kummel Subject: xj: full tim 4wd in JGC So, my wife drives a '96 JGC Limited and loves the thing. But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. Thanks Ed web/gadget guru _________________________________________________________________ Mortgage refinance is Hot. *Terms. Get a 5.375%* fix rate. Check savings https://www2.nextag.com/goto.jsp?product=100000035&url=%2fst.jsp&tm=y&search=mortgage_text_links_88_h2bbb&disc=y&vers=925&s=4056&p=5117 ------------------------------ Date: Wed, 11 Apr 2007 20:59:42 -0700 (PDT) From: Ed Kummel Subject: Re: xj: full tim(e) 4wd in JGC I hear what you're saying...but I really don't want to stop driving my Jeeps...(and my 90 XJ 'IS' my beater!) There's a certain feeling when you're in a Jeep that you don't get in other SUVs...I can't describe it, but I know it whenever I drive one of them! In fact, I'm most likely going to be looking for a newer XJ soon. So increased mileage would be nice. Ed Allen Zylstra wrote: I also have a 96 JGC 4.0 auto with part-time 4x4. I average about 15-16 in suburbia driving. 17-18 highway. Now with the 31s that has dropped about .5 mpg. I wanted a XJ to drive, but the 34mpg of my new beater escort wagon is hard to beat. I save about $40 a week in gas with it and the ZJ stays home most of the time. Allen - -------------------------------------------------------------------- From: ernest breakfield Reply-To: xj-at-digest.net To: xj-at-digest.net Subject: Re: xj: full tim(e) 4wd in JGC Date: Wed, 11 Apr 2007 15:18:30 -0700 >hi ed! > > you didn't mention which motors, gearing or trannys your J**ps have, >but for the sake of discussion i'll ASSuME they have the same gear >ratios and *guess* they're both likely 4.0s with automatics. > > firstly, the AW4 in most XJs is almost always going to outperform >the sloppier ChryCo auto tranny in (most of) the ZJs. > > you also didn't mention what kind and sizes of tires they both have, >and that can make a big difference. (i'm going to go out on a limb and >ASSuME you've already checked to make sure the tire pressures are all >even and correct... or all bets are off.) > > you also didn't mention what kind of driving she's doing; and >"passive and careful" isn't necessarily efficient if she's using the >brakes a lot to scrub off speed she just accelerated to get instead of >allowing the vehicle to coast. > if you're "rarely under 75", you're doing a good percentage of your >time at highway speeds where the torque converter is always locked up >and most efficient. if she's doing most of her mileage around town with >constant starts from a dead stop in the heavier vehicle, her mileage is >never going to be great. (if all other factors were equal, the ZJ should >have a slight advantage on the hwy, as its body style has a lower C.D.) > to be totally fair, you'd both have to switch vehicles for a few >tanks to see how they played out, and determine how much of the >difference between the 2 is the vehicle vs driving style and usage. > > also, it's likely that your XJ has the ill-fated front axle >disconnect that disconnects the front axle from the driveline, removing >a tiny percentage of drag (assuming that it's still working properly). > > as an aside, i wouldn't pay any attention to any trip computer; it's >good for entertainment value at best. > figuring your (her) actual fuel consumption by resetting the trip >odometer to Zero at a fill-up. record how much mileage is on it again at >the next fillup, and divide the number of gallons by the actual miles >reported travelled; you may be surprised at the percentage of >variance... but i doubt you're ever going to see a 3-5 MPG increase in >identical use. > > you can make sure you've got all the regualr service items in good >shape (like making sure the air cleaner is clean), but the cost of >changing out major components to try to achieve an increase in fuel >efficiency isn't likely to be cost-justified in the lifetime of the vehicle. > the sad reality is, if fuel consumption is a concern, unless she has >a legitimate need for a high-clearance 4WD station wagon, she's driving >the wrong vehicle. > > >cheers! >e > > >Ed Kummel wrote: > > So, my wife drives a '96 JGC Limited and loves the thing. > > But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. > > Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. > > So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? > > I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. > > Thanks > > Ed today. - ------------------------------------------------------------------------ "The rule in Silicon Valley is that if Apple leaves the table smiling, the other guy got screwed," - Rob Enderle, independant analyst on the Apple/Cisco iPhone lawsuit - --------------------------------- Bored stiff? Loosen up... Download and play hundreds of games for free on Yahoo! Games. ------------------------------ Date: Wed, 11 Apr 2007 21:14:20 -0700 (PDT) From: Ed Kummel Subject: Re: xj: full tim(e) 4wd in JGC Wow...didn't realize that I forgot so much! Motors are the same 4.0L Tire sizes are the same (30X9.5X15) I don't konw about the tranny... and my wife drives like she has an egg between her foot and the pedals. Me on the other hand I drive like 90% of my body weight is in my right foot I've never checked the gas mileage on the ZJ because the on-board computer is supposedly giving me that information. But since you say that this thing isn't to be relied on, I guess I'll check the mileage the "normal" way. and I don't konw the gearing...I can say that they are all stock...for whatever that's worth. Ed web/gadget guru ernest breakfield wrote: hi ed! you didn't mention which motors, gearing or trannys your J**ps have, but for the sake of discussion i'll ASSuME they have the same gear ratios and *guess* they're both likely 4.0s with automatics. firstly, the AW4 in most XJs is almost always going to outperform the sloppier ChryCo auto tranny in (most of) the ZJs. you also didn't mention what kind and sizes of tires they both have, and that can make a big difference. (i'm going to go out on a limb and ASSuME you've already checked to make sure the tire pressures are all even and correct... or all bets are off.) you also didn't mention what kind of driving she's doing; and "passive and careful" isn't necessarily efficient if she's using the brakes a lot to scrub off speed she just accelerated to get instead of allowing the vehicle to coast. if you're "rarely under 75", you're doing a good percentage of your time at highway speeds where the torque converter is always locked up and most efficient. if she's doing most of her mileage around town with constant starts from a dead stop in the heavier vehicle, her mileage is never going to be great. (if all other factors were equal, the ZJ should have a slight advantage on the hwy, as its body style has a lower C.D.) to be totally fair, you'd both have to switch vehicles for a few tanks to see how they played out, and determine how much of the difference between the 2 is the vehicle vs driving style and usage. also, it's likely that your XJ has the ill-fated front axle disconnect that disconnects the front axle from the driveline, removing a tiny percentage of drag (assuming that it's still working properly). as an aside, i wouldn't pay any attention to any trip computer; it's good for entertainment value at best. figuring your (her) actual fuel consumption by resetting the trip odometer to Zero at a fill-up. record how much mileage is on it again at the next fillup, and divide the number of gallons by the actual miles reported travelled; you may be surprised at the percentage of variance... but i doubt you're ever going to see a 3-5 MPG increase in identical use. you can make sure you've got all the regualr service items in good shape (like making sure the air cleaner is clean), but the cost of changing out major components to try to achieve an increase in fuel efficiency isn't likely to be cost-justified in the lifetime of the vehicle. the sad reality is, if fuel consumption is a concern, unless she has a legitimate need for a high-clearance 4WD station wagon, she's driving the wrong vehicle. cheers! e Ed Kummel wrote: > So, my wife drives a '96 JGC Limited and loves the thing. > But it gets absolutly terrible gas mileage (never better than 17mpg) and she is a passive and careful driver. As a comparison, I drive a '90 XJ Sport and I rarely drive under 75mph and I regularly get 17mpg. > Hitting the computer info center button, in the '96, it says she averages around 15mpg. I would like the Jeep to get better than that. So, I figure that what makes that Jeep different than my 90 is that it's a full time 4wd system. > So, My question is...does the full time 4wd jeep have a different transfer case than one that can be switched between 4wd and 2wd? And is there any kind of mod that can be done to the full time 4wd xfer case to put it in 2wd mode? > I suspect that driving the Jeep in 2wd mode should get another 3-5 mpg out of the jeep and that would make me very happy with gas prices threatening the $3.00/gallon here in Northern VA. > Thanks > Ed - ------------------------------------------------------------------------ "The rule in Silicon Valley is that if Apple leaves the table smiling, the other guy got screwed," - Rob Enderle, independant analyst on the Apple/Cisco iPhone lawsuit - --------------------------------- Expecting? Get great news right away with email Auto-Check. Try the Yahoo! Mail Beta. ------------------------------ End of xj-digest V1 #2552 *************************