shrockworks xterraparts
XOC Decal
Newest Members
Glim, ChossWrangler, Patman, ChargedX, Randy Howerton
10084 Registered Users
Recent Posts
ECXC 2024!
by Tom
23/04/24 04:27 PM
2002 Door Opening Trim
by OffroadX
01/04/24 08:32 PM
XOC Still Lives
by OffroadX
01/04/24 08:31 PM
Shout Box

Who's Online
0 registered (), 139 Guests and 0 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#97138 - 22/05/01 11:17 AM Towing capacities
onemadfool Offline
Member

Registered: 12/01/01
Posts: 150
Loc: Reading, PA
I did a search and did not come up with a post covering this question. I am just curious...why does the A/T have a higher towing capacity than the M/T? In my owners manual it says the a/t can tow 5000lbs, and the m/t is only 3500lbs. Why is that? Does it have to do with the way they are geared?

Any info is appreciated.

Onemadfool

------------------
DO YOU LIKE PANCAKES?
---------------------
2001 XE V6 4x4 5SPD Aztec Red AOL IM - mtg junkie
communities.msn.com/OnemadfoolsXterraShrine
_________________________
"If I wanted smoke blown up my ass, I'd be at home with a pack of cigarettes, and a short length of hose." --The Simpsons

Top
#97139 - 22/05/01 11:36 AM Re: Towing capacities
wqbang Offline
Member

Registered: 16/08/00
Posts: 1930
Loc: Auburn, WA
Liability issues. Nissan underrates the MT's towing capacity so that it doesn't have to warranty smoked clutches owned by people who don't know how to tow.

In most cases *with proper technique*, a manual tranny can tow more than an auto.

------------------
:wq!
Senior Member - Southeast Xterra Club
Tread Lightly!
_________________________
Tread Lightly!

Top
#97140 - 22/05/01 03:18 PM Re: Towing capacities
GordP Offline
Member

Registered: 02/05/01
Posts: 79
Loc: White Rock, B.C. Canada
Quote:
Originally posted by onemadfool:
why does the A/T have a higher towing capacity than the M/T? In my owners manual it says the a/t can tow 5000lbs, and the m/t is only 3500lbs



In a round-about way, I guess you could say gearing is one factor.

The manual transmission has "hard" gears, with a fixed/known 1st gear. On the surface, comparing gear-ratios, it appears the auto tranny has poorer gearing...

But - the auto tranny has a torque convertor! Below the stall-speed, the fluid is in "shear", and the convertor performs a "torque-multiplying" function. American General and others specify a multiplier of 2x for this. So, rather than a first-gear of 2.5:1 (for example), the auto tranny's convertor makes this more like a 5:1 first gear. Significantly lower than the Xterra manual-tranny.

There are domestic truck manual transmissions with "granny" gears, featuring 5.6:1, 6:1 or even 7:1 first gears. It's rare that you can use these on the street, but towing or getting a heavy load moving is one great use for them.

In the case of the Xterra, I think it's simply the lower-effective-gearing offered by the automatic.

-GordP

------------------
_________________________
2001 Solar Yellow XE (S/U/P)
31" ProComp M/T tires
tow hooks, storage shelf, Warn hubs

Top


Moderator:  Ramness 

shrockworks xterraparts
XOC Decal