KV6 2.5: power & torque loss?

Dorchester2 · 24th July 2021, 09:09

I would appreciate very much to know whether some of us owners of a KV6 2.5 have tried to get some figures from a test bench?

I presented my car last Thursday to such a test and the figures were appalling:

- Power 140.5 bhp --> 35 bhp loss! 20%!!!

- Torque 146.5 ftlb --> 30 ftlb loss! 17.3%!!!

They complained they had difficulties to make the test because of the auto box which was systematically downgrading in gear even in the 4, 3, 2 gears!

I'd never thought that the auto box could downgrade to the immediate gear below even in a 'stuck' position as 4, 3 or 2!

But if so I have the feeling that the tests couldn't have been done in the 5th gear... May it be the secret of those weird and bewildering figures?
Would somebody explain where lies the flaw or the mystery?

Because my engine is very responsive, I've no difficulty to accelerate very quickly uphill even on hard slopes, I can very easily overtake with an immediate kick down that gives me a real kick in the ass, every service had been done, VIS motors swapped in 2017, brand new iridium spark plugs since the end of 2017, belts pulley & pump swapped 6 months ago, oil & filter changed once a year and the like. And TOAF detection of errors gives absolutely nothing wrong: every bit is in perfect order. Even my tyres are slightly over inflated.

So why such a ginormous discrepancy between the theoretical figures indoors and the real efficiency in the real life???

I know that impressions & feelings don't give any evidence: but all the same I'm not a beginner, I hope I'm not schizophrenic either but nonetheless the gap looks utterly unbelievable at least for me.

Thank you for your wise comments & reactions.

24th July 2021, 09:09	#1
Dorchester2 incurable Rover addict Rover 75 Saloon V6 2.5 1999 - Rover 25 1.4 2002 - Rover 214i cab 1994 - Rover P5b coupe 1968 Join Date: Sep 2017 Location: Bioule. South West of France. Posts: 1,643 Thanks: 612 Thanked 385 Times in 223 Posts	KV6 2.5: power & torque loss? I would appreciate very much to know whether some of us owners of a KV6 2.5 have tried to get some figures from a test bench? I presented my car last Thursday to such a test and the figures were appalling: - Power 140.5 bhp --> 35 bhp loss! 20%!!! - Torque 146.5 ftlb --> 30 ftlb loss! 17.3%!!! They complained they had difficulties to make the test because of the auto box which was systematically downgrading in gear even in the 4, 3, 2 gears! I'd never thought that the auto box could downgrade to the immediate gear below even in a 'stuck' position as 4, 3 or 2! But if so I have the feeling that the tests couldn't have been done in the 5th gear... May it be the secret of those weird and bewildering figures? Would somebody explain where lies the flaw or the mystery? Because my engine is very responsive, I've no difficulty to accelerate very quickly uphill even on hard slopes, I can very easily overtake with an immediate kick down that gives me a real kick in the ass, every service had been done, VIS motors swapped in 2017, brand new iridium spark plugs since the end of 2017, belts pulley & pump swapped 6 months ago, oil & filter changed once a year and the like. And TOAF detection of errors gives absolutely nothing wrong: every bit is in perfect order. Even my tyres are slightly over inflated. So why such a ginormous discrepancy between the theoretical figures indoors and the real efficiency in the real life??? I know that impressions & feelings don't give any evidence: but all the same I'm not a beginner, I hope I'm not schizophrenic either but nonetheless the gap looks utterly unbelievable at least for me. Thank you for your wise comments & reactions. __________________ Rover 75 V6 2.5 Auto Connie born 1 July 1999, 24 kOhms resistor, 10 kOhms manual starter, full E85, modified airbox, full derestricted SS exhaust line, power & torque remap -> 202 bhp This vehicle was the 7,517th 75 to run off the production line, out of 112,381 This vehicle was the 1,190th 75 2.5 V6 Contemporary to be made out of 8,214 This vehicle was the 2,032nd 75 in Atlantic Blue Pearlescent (code: JEY) to be made out of 2,572 Atlantic Blue Pearlescent 75s Last edited by Dorchester2; 24th July 2021 at 09:15..