Why the power difference ??
Submitted: Friday, Aug 15, 2008 at 20:42
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Stephen M (NSW)
Was just reading some specs on a lot of the new model 4wdrives. Seems to be a fair difference (roughly 30kw on average) between auto & manual seems to affect turbo diesel only.The only one that didnt make any difference between auto & manual were the prados/cruisers/navara. Is the difference due to transmissions not being able to handle the extra power/torque ??? The mitsi showing the same figures for the triton either manual or auto but the pajero there is a difference between the two but running the same motor (3.2 t/d) ?? Patrol for example (3 litre) showing 118kw/380 torque for the 5 speed,but the auto showing 118 (same) but the torque down to 354 ??. Pajero 118kw/381 torque in manual but the auto more kw 125kw but lower torque 358 but both running the 3.2 t/d ?? Makes it all confusing when looking at power figures and trying to work out the best options. Regards Steve M
Reply By: Member - Madfisher - Friday, Aug 15, 2008 at 22:10
Friday, Aug 15, 2008 at 22:10
Hi Steve,
Noticed same thing my self, I wonder has it got anything to do with pollution controls!.
Cheers Pete
AnswerID:
320844
Reply By: Member - Olcoolone (S.A) - Friday, Aug 15, 2008 at 22:31
Friday, Aug 15, 2008 at 22:31
Could be a number of things like driveability, gearbox long term reliability, economy, NVH and many other things.
AnswerID:
320847
Reply By: Member - Alan H (QLD) - Saturday, Aug 16, 2008 at 07:35
Saturday, Aug 16, 2008 at 07:35
I would expect auto transmissions to have a lower torque due to lack of solid coupling (clutch). Most autos have have a fluid coupling which has inheriit "slip" hence the difference for the same engine. (this why we have torque converter locks)
Torque would also be governed by the mechanical advantage of gear ratios. Check ratios in transmissions and diffs.
Alan
AnswerID:
320862
Follow Up By: Nomadic Navara - Saturday, Aug 16, 2008 at 12:13
Saturday, Aug 16, 2008 at 12:13
The power & torque figures are taken without the clutch or torque converter in
the loop, not at the input to the gear box (ie power at the flywheel.)
PeterD
FollowupID:
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Reply By: Member - John F (NSW) - Saturday, Aug 16, 2008 at 07:58
Saturday, Aug 16, 2008 at 07:58
I think it may be that the auto gives a torque multiplication effect, so not as much torque needs to be produced. Perhaps some of the trannies are not rated to handle the torque produced by the motor, which is then de-rated.
Regards, John.
AnswerID:
320863
Reply By: Nomadic Navara - Saturday, Aug 16, 2008 at 12:18
Saturday, Aug 16, 2008 at 12:18
You quote a vehicle with less torque for the auto version. The Disco D1 & D2 both have a little more power in the auto version (don't know about the D3.)
There are several factors that influence the manufacturers final product, you will have to ask them about their decision, it is not an industry standard.
PeterD
AnswerID:
320892
Follow Up By: Stephen M (NSW) - Saturday, Aug 16, 2008 at 14:14
Saturday, Aug 16, 2008 at 14:14
Hi Peter, I didnt look at the disco's but interesting they are the opposite. Didnt think it was an industry standard but was just wondering why the power difference either way. Was presuming due to been auto (box not as strong as say a manual) but the disco's obviously throw that theory out the window. Regards Steve M
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