BHP... how much is too much?
Discussion
I think there is a sweet spot, sort of adequate plus, i.e. enough power to do its job and a little bit extra, that is the 100 bhp/tonne spot, less and its varying degrees of less fun, as you go higher it gets more interesting, but actually will make cock all difference to how fast you get somewhere, unless you plan on breaking speed limits by a huge margin.
Not enough power was our Fiat 500, the original one, sort of ok round town but flat out all the time and not really enough power to mix it with traffic, hills were taken in second and pulling out onto a busy road took some planning, but that is down to driver skill and anticipation rather than just power, in a slower car you adjust your expectations, but the Fiat was just not enough to feel comfortable, at say 30 - 40 bhp it would have been fine.
You can have too much, if the rest of the car isnt up to it, brakes suspension, cooling etc, even the shell can sometimes not be up to the torque output of a bigger engine
There does seem to be an element on here utterly fixated by power and torque numbers ,like playing top trumps, its the 535D thing, its the Mercs with mega firepower but an automatic box, some seem prepared to buy and drive anything as long as it has the biggest numbers and reject anything under some arbitrary amount
because it isnt, I have done it myself, Saabs and Volvos produce some good numbers for not much money and are decent cars but they are generally a one trick Pony, i.e. straight line speed, I am sure some convince themselve a decent, sweet handling car is crap as it doesnt have the right badge and twelvetey thousand Clarksons of power, plus some soft touch interiors and loads of "toys".
Power is important but it shouldnt be the only consideration.
Not enough power was our Fiat 500, the original one, sort of ok round town but flat out all the time and not really enough power to mix it with traffic, hills were taken in second and pulling out onto a busy road took some planning, but that is down to driver skill and anticipation rather than just power, in a slower car you adjust your expectations, but the Fiat was just not enough to feel comfortable, at say 30 - 40 bhp it would have been fine.
You can have too much, if the rest of the car isnt up to it, brakes suspension, cooling etc, even the shell can sometimes not be up to the torque output of a bigger engine
There does seem to be an element on here utterly fixated by power and torque numbers ,like playing top trumps, its the 535D thing, its the Mercs with mega firepower but an automatic box, some seem prepared to buy and drive anything as long as it has the biggest numbers and reject anything under some arbitrary amount
because it isnt, I have done it myself, Saabs and Volvos produce some good numbers for not much money and are decent cars but they are generally a one trick Pony, i.e. straight line speed, I am sure some convince themselve a decent, sweet handling car is crap as it doesnt have the right badge and twelvetey thousand Clarksons of power, plus some soft touch interiors and loads of "toys".
Power is important but it shouldnt be the only consideration.
The amount you 'need' is very low indeed. I'm currently commuting around 700 miles a week in a 190D with about 50 bhp/ton. Overtakes need some planning, it's something like 20 seconds to 60, but it happily cruises at beyond the NSL. I'd say that's all the power you actually need for a car as transport.
"How much is too much" is a different question. My old Sapphire Cosworth was almost bang on 300 bhp/ton. Based on my experience there's not much point in having any more than that in something that's going to be predominately a road car.
"How much is too much" is a different question. My old Sapphire Cosworth was almost bang on 300 bhp/ton. Based on my experience there's not much point in having any more than that in something that's going to be predominately a road car.
JDMDrifter said:
100-150bhp per tonne is adequate I'd say. I think anything more than 400 isn't really usable on a daily basis.
Have to agree, the XJR has 370 stock. Mine was a little more due to the Zorst. Rarely used full power, sport mode even less. In the wet booting it in anything less than a straight line would get the tail wagging, entertaining but not for public roads if you have a social conscience!JagXJR said:
Have to agree, the XJR has 370 stock. Mine was a little more due to the Zorst. Rarely used full power, sport mode even less. In the wet booting it in anything less than a straight line would get the tail wagging, entertaining but not for public roads if you have a social conscience!
It's not about using the full bhp though. My Mustang has a perfectly contained and controllable 462hp in a 1600kg car and it can certainly be deployed safely on appropriate public roads. It has to be borne in mind that it is the availability of large wads of that power at a millisecond's notice that is important, not using all of it all of the time.
However, I think most can respect the power and drive accordingly. I am probably more likely to fractionally lose the back end of the Fiesta in th erain than I am the Mustang as I drive it harder relative to it's overall power...if you see what I mean?
McWigglebum4th said:
skyrover said:
personally.... I believe 100bhp/ton should be a minimum on all future cars sold
I'd love to know your thinking as it sounds like total horses
tI've driven a landrover with 115Bhp with a total train wieght including the trailer of just over 5000Kg
23bhp/Ton
And it wasn't dangerous
Having done plenty of towing in my time you can't have too much power (nor too big a set of brakes)
skyrover said:
McWigglebum4th said:
skyrover said:
personally.... I believe 100bhp/ton should be a minimum on all future cars sold
I'd love to know your thinking as it sounds like total horsestI've driven a landrover with 115Bhp with a total train wieght including the trailer of just over 5000Kg
23bhp/Ton
And it wasn't dangerous
Having done plenty of towing in my time you can't have too much power (nor too big a set of brakes)
My car weighs 1430Kg, has 200BHP, that's what..142BHP/Ton? It's not really quick in absolute terms, but with a 0-60 time of 7.5sec and 150mph topspeed, it's adaquatly fast. It's a great mile-muncher for long distances, and in town I'm usually driving over the limit most of the time, without really trying (The last photo cost me €130 and 3 points, I love living in Germany :-) )
i guess it depends on your driving style. the op seems to think a 150bhp 2 ton estate is his ideal, so i guess that's a family car where safety and economy are important.
my perfect daily would be a 300bhp rally special as most of my driving is on congested 8 lane roads where mad max would be seen as driving miss daisy
my perfect daily would be a 300bhp rally special as most of my driving is on congested 8 lane roads where mad max would be seen as driving miss daisy
Problem I have with increasingly fast family transport is the fact it means sportscars have to be absurdly quick to even get away from a hatchback or derv repmobile.
0-60 in 6 seconds is no longer quick enough for the masses when it comes to things like the Elise, as people expect their sportscars to be able to blow away everything else.
If regular stuff was slower, would mean sportscars don't need to crack the ton in under 10 seconds. It all gets a bit silly IMO.
0-60 in 6 seconds is no longer quick enough for the masses when it comes to things like the Elise, as people expect their sportscars to be able to blow away everything else.
If regular stuff was slower, would mean sportscars don't need to crack the ton in under 10 seconds. It all gets a bit silly IMO.
I think it depends on the sorts of roads you drive on. The B roads around my house involve speeds of between 45mph and 60mph, so not too demanding of power, and to corner in balance of course needs very little power (just enough to offset mechanical drag and achieve balance). I reckon I drive down those b roads in my ~1400kg daily driver having fun using only about 60 to 80bhp or half that if I'm not in the mood. On the other side of things, faster dual carriageways with roundabouts and traffic lights etc would quickly become boring with only 80bhp. My daily driver has 163bhp and I think that's about my minimum - ideally I think I'd have about 200bhp. I've owned faster cars, such as my present second car with 260bhp and 740kg, but if you use all the power even briefly you're illegal very soon indeed, so it only really gets used on track.
Interesting topic. Personally I wouldn't want an overly powerful car everyday, I think I'd get too used/ bored with it - 150bhp would suit me well. The weekend toy can be as powerful as I want it to be 
e.g The Skoda has 150bhp (I think or 160bhp), and the Porsche has 250bhp. There's a nice difference in power to keep the Boxster interesting and the Superb still fast enough day to day.
e.g The Skoda has 150bhp (I think or 160bhp), and the Porsche has 250bhp. There's a nice difference in power to keep the Boxster interesting and the Superb still fast enough day to day.
Edited by Dalto123 on Monday 5th August 23:38
leafspring said:
jimbobsimmonds said:
So you form all your opinions on Top Gear or do you have personal experience. I have driven the Vectra VXR many times and although I would never own one, or buy one (for lots of different reasons) I was impressed with its ground covering ability and complete lack of Clarksonesque epic FWD (2nd gear on full lock in the damp...) understeer-into-a-bush-ness.
And in answer to your original question. I have 300bhp+ in an FWD saloon and still think I need more (and a LSD).
Clarkson is a ham fisted baffoon.And in answer to your original question. I have 300bhp+ in an FWD saloon and still think I need more (and a LSD).
I have driven a Vectra VXR (admittedly it was 2nd hand and had 70k+miles under its belt).
On a flat dry road at anything over 1/4 throttle, from a rolling start or stationary... it would not accelerate in a straight line, it just torque steered in which ever direction it felt suited it (usually right)
Once you're out of town away from traffic I agree it was good at covering ground and brakes where excellent... still a Vectra though
Maybe i'm used to FWD saloons but torque steer I don't normally find an issue...
I had 174bhp in my old 120d, which weighed 1365kg, returning a bhp/tonne ratio of 127bhp/tonne. I thought that was more than adequate - sure, it may have taken a bit of time to overtake another car doing 80mph (in Germany, of course), but for 95% of the time I never found myself wanting extra power. It was enough to get around town, accelerate safely onto a motorway, and do a couple of 46mph everywhere brigade overtakes on NSL roads.
I've been driving a Mk4 Golf GTi for the past week (the 150bhp) version and I feel that's about adequate. Enough power to keep you moving, but not enough to get you into too much trouble.
I've been driving a Mk4 Golf GTi for the past week (the 150bhp) version and I feel that's about adequate. Enough power to keep you moving, but not enough to get you into too much trouble.
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