5-speed vs 8-speed on 2014 SRT ? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WK2 Grand Cherokee Forum > 5-speed vs 8-speed on 2014 SRT ?

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFlowmaster's Force II Axle-back exhaust system for the 201FS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 11-15-2013, 04:54 PM   #1
darkhue
Registered User
 
Join Date: Aug 2013
Location: dubai, UAE
Posts: 17
5-speed vs 8-speed on 2014 SRT ?

So I heard from friends that the 5-speed is actually better than 8-speed in performance (disregard economy for this topic) for the 2014 SRT. I argued that more gears allow faster acceleration times due to gear ratios when compared to 5-gears. But I kept hearing that 5-speed is faster in the long run.

Can someone give me a detailed and informative discussion about 5-speed vs 8-speed and the difference in performance ?

Thanks !

darkhue is offline   Reply With Quote
Unread 11-15-2013, 06:04 PM   #2
ArloGuthroJeep
Mr. Hyde!
 
ArloGuthroJeep's Avatar
2004 WJ 
 
Join Date: Mar 2005
Location: Boulder, CO
Posts: 23,079
I can't speak towards this specific case, but in general if you spend too much time between gears (shifting a la 8 speed transmission) then it could hurt your acceleration. There are DSG transmissions that can get around that though.
__________________
'04 WJ, 6" Clayton LA's, 242 SYE, 35" BFG MT KM2's, 4.56 gears, & D44a locked
'14 WK2 Limited w/5.7L, ORAI, & Tow Package
ArloGuthroJeep is offline   Reply With Quote
Unread 11-15-2013, 06:42 PM   #3
bmoney12
Registered User
2014 WK 
 
Join Date: Sep 2013
Location: Fairfax, VA
Posts: 35
I would think if anything the 8 speed is as fast if not faster. The 8 speed should have quicker shifts which would mean less loss of power. The gearing might be better to.
__________________
2014 Jeep GC Limited V8
2014 Mercedes CLA45 AMG
bmoney12 is offline   Reply With Quote
Unread 11-16-2013, 02:01 AM   #4
darkhue
Registered User
 
Join Date: Aug 2013
Location: dubai, UAE
Posts: 17
Two replies into the topic and I already have two different opinions !! It seems like the whole 5-speed vs 8-speed topic is not clear with regards to performance impacts.

Last edited by darkhue; 11-16-2013 at 02:22 AM..
darkhue is offline   Reply With Quote
Unread 11-16-2013, 02:50 AM   #5
Gunny7
Registered User
2014 WK 
 
Join Date: Nov 2013
Location: Houston, Tx
Posts: 134
ZF 8 speed is computer controlled. Same transmission as in the Audi and a few other high end.
Can be set to shift fast as you want.
Can shift too fast to perceive almost.
I think I read 0.200 seconds between shifts.
micro seconds.
And it can skip gears going up or down if it perceives the need.
All in the program.
Alpar has some good info about this.
Not like a regular transmission.
Much, much of an improvement.

Last edited by Gunny7; 11-16-2013 at 07:21 AM..
Gunny7 is offline   Reply With Quote
Unread 11-16-2013, 05:50 AM   #6
ncsucarjock88
Registered User
 
Join Date: Jan 2013
Location: raleigh, nc
Posts: 14
http://www.trucktrend.com/roadtests/...rt_first_test/
Having driven the 8 speed behind the normal Hemi and the diesel, I can say it's am impressive transmission. I'd definitely go for the 8 speed over the 5 speed. Is there much difference in acceleration times? No, but it does allow for faster manual shift times, holds gears, will rev-match downshifts, and will double downshift... The torque converter is also particularly tight and locks up almost instantly, which results in a very direct drive feel.

The new automatics, and especially the ones from ZF, (who designed the torqueflite8) are just damned impressive pieces of machinery.
ncsucarjock88 is offline   Reply With Quote
Unread 11-16-2013, 06:26 AM   #7
ColdCase
My Reality Check Bounced
 
ColdCase's Avatar
2011 WK 
 
Join Date: Sep 2009
Location: New England
Posts: 3,553
Any one see any comparison test? What about a few time slips? Otherwise we are all guessing and making assumptions of how well the engine and auto mate up. More speeds are important for tiny engined like Audi uses or diesels where power bands are narrow. Could be a disadvantage with more power mated to a well developed transmission.
__________________
2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6, 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
ColdCase is offline   Reply With Quote
Unread 11-16-2013, 06:51 AM   #8
bmoney12
Registered User
2014 WK 
 
Join Date: Sep 2013
Location: Fairfax, VA
Posts: 35
Quote:
Originally Posted by ColdCase
Any one see any comparison test? What about a few time slips? Otherwise we are all guessing and making assumptions of how well the engine and auto mate up. More speeds are important for tiny engined like Audi uses or diesels where power bands are narrow. Could be a disadvantage with more power mated to a well developed transmission.
It's pretty close but the 8 speed might be a tad faster.

8 Speed

http://www.caranddriver.com/reviews/...rt-test-review

http://m.trucktrend.com/roadtests/su...est/index.html

5 Speed

http://www.caranddriver.com/reviews/...8-test-reviews

http://m.trucktrend.com/roadtests/su...est/specs.html
__________________
2014 Jeep GC Limited V8
2014 Mercedes CLA45 AMG

Last edited by bmoney12; 11-17-2013 at 09:07 AM..
bmoney12 is offline   Reply With Quote
Unread 11-16-2013, 07:04 AM   #9
jay-h
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2006
Location: , NJ
Posts: 4,276
When other Chrysler products went to 8 speed, performance was measurably improved.
__________________
My toys
'89 Wrangler YJ
'47 CJ2-A

wife's toys
97 Grand Cherokee (ZJ)
87 MB 560SL roadster
jay-h is online now   Reply With Quote
Unread 11-16-2013, 07:34 AM   #10
Gunny7
Registered User
2014 WK 
 
Join Date: Nov 2013
Location: Houston, Tx
Posts: 134
What I like about the 8 speed is it is the ZF. Chrysler calls it the TorqueFlight8 but it is the ZF.
Built at the new plant built just for this.
The agreement with ZF is that, as needed, ZF can use transmissions from this plant.
Chrysler will make way more transmissions than ZF ever had.
But that means this plant has to make these things to ZF Quality Control.
Will go into little bitty 4 cylinders to big Diesel trucks.
Gunny7 is offline   Reply With Quote
Unread 11-16-2013, 09:30 AM   #11
loveracing1988
Registered User
 
Join Date: Jan 2013
Posts: 649
Quote:
Originally Posted by Gunny7 View Post
ZF 8 speed is computer controlled. Same transmission as in the Audi and a few other high end.
Can be set to shift fast as you want.
Can shift too fast to perceive almost.
I think I read 0.200 seconds between shifts.
micro seconds.
And it can skip gears going up or down if it perceives the need.
All in the program.
Alpar has some good info about this.
Not like a regular transmission.
Much, much of an improvement.
Our V6 grand will skip gears if you need it to, but in my ram it doesnt, it will keep going up gears one by one until it gets to peak power.
loveracing1988 is offline   Reply With Quote
Unread 11-17-2013, 08:25 AM   #12
darkhue
Registered User
 
Join Date: Aug 2013
Location: dubai, UAE
Posts: 17
Does anyone have concrete evidence of performance differences between the two gear options ?
darkhue is offline   Reply With Quote
Unread 11-17-2013, 02:12 PM   #13
jay-h
Registered User
1989 YJ Wrangler 
 
Join Date: Dec 2006
Location: , NJ
Posts: 4,276
Quote:
Originally Posted by darkhue View Post
Does anyone have concrete evidence of performance differences between the two gear options ?
The V6 Charger went from 5 speed to 8 speed it dropped 1-2 seconds from 0-60 and increased 4mpg.

(according to Allapr "from around 7.7 to 8 seconds with the five-speed, they are now claimed at 6.6 seconds, which, incidentally, is identical to that of the 2006 Charger R/T...")

more in article
http://www.allpar.com/reviews/2012/c...-blacktop.html
__________________
My toys
'89 Wrangler YJ
'47 CJ2-A

wife's toys
97 Grand Cherokee (ZJ)
87 MB 560SL roadster
jay-h is online now   Reply With Quote
Unread 11-18-2013, 08:59 AM   #14
darkhue
Registered User
 
Join Date: Aug 2013
Location: dubai, UAE
Posts: 17
Quote:
Originally Posted by jay-h View Post
The V6 Charger went from 5 speed to 8 speed it dropped 1-2 seconds from 0-60 and increased 4mpg.

(according to Allapr "from around 7.7 to 8 seconds with the five-speed, they are now claimed at 6.6 seconds, which, incidentally, is identical to that of the 2006 Charger R/T...")

more in article
http://www.allpar.com/reviews/2012/c...-blacktop.html
Thanks for the link, that's a great review.

Are there any similar studies done on newer cars ? Say the 2014 Jeep for example ?
darkhue is offline   Reply With Quote
Unread 11-18-2013, 10:20 AM   #15
overland_HO
Registered User
2013 WK 
 
Join Date: Jun 2008
Location: SLC, UT
Posts: 229
Oh, this should be a fun topic...
__________________
13 Jeep G.C. Trailhawk HEMI/QDII/QL/ORAII
14 Chevy 3500 Duramax/Allision | 26' TT | ATVs
overland_HO is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.