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Which is the true power figure for a 172

Hi guys, Im new here.

Just wondering Renault claim the 172 car has 172bhp, yet when converted to kilowatts its only 124kw?

where it shouldve been 128kw to equal 172bhp.

cos the focus ST170 has 127kw....which is spot on.. 170bhp=127kw

thanks heaps!
  CTR EK9 turbo

Hello, and welcome. The Renaultsport Clio 172 has 172 bhp. Does +/- 2 bhp make any difference anyway?
  Silver Fabia vRS

Its the power at the wheels you want to be worried about!

An ST170 may have 170bhp but if it has 50% transmission loss (it wont be that high but for purposes of the demonstration) you only have 85bhp in real terms.

The 172 loss is around about 27% using the latest Rolling Road report, so you get about 125bhp at the wheels.


ClioSport Club Member
  E90 LCI 330d

The "Clio 172" has 172ps and not 172bhp apparently.


To convert from ps to bhp you just divide by 1.01387

So 172ps = 170bhp

Not that 2bhp makes any difference anyway!
  172 Cup

Where does it say the 172 has 172ps?? I have never seen this documented. I have however seen alot of Renault literature stating 172bhp.

All the literature says 172bhp, but it is actually 172ps, and in real terms most people on the rollers with 172s are getting around 165bhp (with no mods).

Does it actually matter for a few bhp?? Not on your nelly... bloody quick and lots of fun either way.

my personal opinion is that the 172 has no where near 172 BHP.. the figures by reno are ps.. ie - without any ancilliaries.

I would like to see one on an engine dyno to confirm this.

probably yes, more like 165 bhp realistically.

bhp is not the only consideration though. torque and gearing is extremely important too.


I prefer the Jap method for quoting BHP...take the Skyline for example. Quoted @ 280bhp, actual more like 330bhp Only cuz the Japs cant declare more than 280bhp...hahaha! Imagine picking up your 172 and it actually had 250bhp - NICE!


ClioSport Club Member
  E90 LCI 330d

Thats the 280ps (aka 276bhp) "gentlemans agreement" and yes a *lot* of those Jap nutter wagons had a lot more!

The 22B Scooby is a prime example...

The 2.0 litre WRX/STi has 276bhp, so why has the 2.2 litre twin-turbo 22B only got the same power?!

Answer, they dont, it was nearer 350bhp apparently!

Nope, the 22B had about the same power output on the rollers as the 2 litre STis or WRXs. If you are interested in hundreds of dynoplots, see Interesting. And there are pictures of my EVO6 there as well...

If you do a quick conversion.

124 KW = 166BHP

I commented on this a while back on another post, nobody picked up on it! No wonder the vast majority of 172s post this figure!

Got my car rolling roaded today. I have piperx viper , scorpion exhaust + superchip. Fueling was spot on but power at wheels was 121.5 Bhp and at fly was 168 Bhp. Torque was 139 ib/ft. Bit low concidering the mods. The torque and power curves cross over at 6000+ rpms.


Hi Chun,

heres a good tip..

have a plot done on good rollers PRIOR to any mods..

always take the motor back to the same rollers.

The piper could be losing you 10bhp !, the superchips is designed for a standard car, and the scorpion has probably NEVER been tested on a 172.. just made to fit !.

sorry to sound ott... but a lot of these mods are serious power drainers.


(If I can see a plot, before.. and after.. the mods individually.. I will retract what I said for any item mentioned.. without a true, controlled plot... they quote power figures outa their bottys !!)


Hi Chun.. the answer is.. I DONT KNOW

neither does anyone.. cos (as far as I am aware) it has never been objectively tested.

that being the case, It could be loosing you a whack of gogo, or, adding to it..

in my experience, the ones that actually gain anyything are few and far between.

Mr PIPER ???... show me the graph.. on a 172 ??


I dont have the original exhaust, to be honest the exhaust didnt add anything to the performance of the car. But the viper + chip seemed to have added some good low end. Interesting thing is the capacity of the viper is a lot less than the standard induction system.


Hiya Chun.. half the problem is that the induction kit adds nice noise, (it is actually possible to read the car better .. but thats an aside lol...)

the noise really DOES add to the experience and the whole kit strapped to yer ass feels better

the noise from a lot of sports cars is actually contrived..

I am NOT saying you are not gaining (although I am strongly of the opinion that you probably are not - until proven wrong. ) but, without objective testing, these things are often a waste of dosh, IF, you buy them for performance.. if the noise / sound is what you are after, then they are worth probably double LOL...

You can take any well established engine tuning catalogue.. say a kent engine (ford Xflow).. read the adverts.. add up the bhp for all addons available for that lump.. I kid u not.. you could have 300 bhp for peanuts.. ok, thats a joke.. but the figures dont add up.!

the manufacturer would NOT miss out on an opportunity to increase performance at no expense..

Sorry for the essay its one of me pet hates...


I just need to know why my cars running down on power. Ao any help is good. Reading various reviews on the net the piperx viper seems to be a good kit. Chip has helped but havent tested it just as yet. And the exhaust didnt take away performance, if anything my car went faster than m8s 172 after the exhaust.

  VW Transporter 174

You can estimate bhp figures for cars by use of a simple equation.
Power(BHP)=total drag x mph/375
But first you need to know the tested top speed of car (clio 138?) the coefficient/drag and the frontal area of car (average 19-23 sq f)

rolling resistance power 0.013 x weight lbs ???? x top speed (138)/375 =?????

air resistance power= frontal area(21?) x cd x0.00256 x top speed (138)/375 =????

add the two answers together to get a power at wheels and then add 15% for power at fly wheel to account for transmission loses.
Id like to know nicks (tested) top speed on laughing gas.


172 Slayer

ive had that formula for ages, but who the hell knows the frontal area of their car!? ive searched high and low to no avail.

But it has some flaws like if you hit the limiter in 5th, then your gonna be doin a top speed of what ever the ratio dictates @ that rpm, but your gonna have more power thent the result of the equation because one of the factors (speed) cannot be tested accurately and with it bouncin off the limiter, your gonna have some in reserve.

ak, absolutely, the hill power is good kit.. as all of Nicks stuff is.

there is possbily more to gain if Nick can sort the lean mix out at WOT.

Nick tests his stuff, piper just seem to want to make money.

if there is a test done on the piper that shows an improvement, then cool.. but as of yet, there isnt.. thats where I am coming from


Captain I think maybe the piper isnt a whole load better than the standard induction system. It has better heat sheilding but has less capacity and area to absorb air than the standard insuction system. So im currently buying some heat sheilding and a performance element to try out the standard induction system again. As well as this Im going to run bigger bore pipes from the front of the car. I think this would make the standard kit better than the piper stuff.

  172 sport,

i spoke to nick hill yesterday and ne recons 163 bhp and argents kit was 6-7 bhp better than standard but says more likely to be 10-15 bhp increase when hes soughted the fueling prob out also he said most aftermarket filters are tested with the bonnets open and that its usually the case that when you shut the bonnet they give less bhp than the o/e that sucks but he is the daddy