How Fast is Too Fast for the Road?

[MattHall91]

This Sunday's ponder has led me to think about how much power and performance can you actually use on the public roads.

The skill of the driver obviously plays a part, but although many of us long for a 500bhp+ supercar, unless you visit a track every week it's pretty must wasted.

So what do we think? 200bhp? 300bhp? 0-60 in 6 seconds? 5 seconds?

I regularly ride in a 235i and that is about the limit of usability IMHO.

[anonymous-user]

I drive a diesel estate car.

If i even remotely "try", even it makes an absolute mockery of every UK speed limit.

[gavsdavs]

Actual speed you can use is limited by law.
However, having bucketloads of torque allows less gearchanges and a less frantic time overtaking, for example.

[MattHall91]

Max_Torque said:

I drive a diesel estate car.

If i even remotely "try", even it makes an absolute mockery of every UK speed limit.

Likewise with my 2.2 Mazda 6 diesel company car.

But I can still enjoy full throttle for a long enough time to appreciate it.

[Codswallop]

Power to weight also plays a part. I currently have in the region of 355bhp in a large coupe, and it's too much for the road imo. I certainly had more fun accelerating hard through the gears in lower powered vehicles. Luckily the big V8 is fun regardless of speed thanks to the interaction of the controls and the noises it makes

[paintman]

"How Fast is Too Fast for the Road?"
The speed you were doing before you wound up in the ditch.

[MattHall91]

paintman said:

"How Fast is Too Fast for the Road?"
Usually slightly less than what you were going before you wound up in the ditch.

Good point! I managed to make a mess of mine and someone else's car with only a 75bhp Fiesta.

Driver plays a significant part!...

[GetCarter]

It's nothing (well almost nothing) to do with speed, but torque and power. Up here in the Highlands If I want to overtake a couple of caravans, I want to be T.E.D. (Time Exposed to Danger) for the least possible time.

40-60 and 50 -70mph in second or third are the important numbers for me.

Also, BHP means nothing without relevant weight as part of the equation. I recently had a car with a miserable 260bhp, that did 0-60 in 2.8 seconds - faster than all those so slow Lambo and Fezza dogs . (Point is, It was only 640kg in weight).

Edited by GetCarter on Sunday 1st February 14:33

[f1nn]

I'd say the M135i was borderline too quick to use its performance on the road, well in terms of being able to use its performance routinely in relation to other road users.

I've just bought an E90 330D and that strikes me as a good real world compromise. of course you can use far more power in certain circumstances, but 0-60 in high 6, 100 in 15 and 155 flat out coupled with a lump of diesel torque seems enough.

[Troubleatmill]

On a very cold slushy motorway - my 505bhp car was being overtaken by Fiat Pandas.
Anything more that 50 mph and the tail end wants to kick out.
You could also drive at 60mph in 1st.


James Hunt said that the most fun car he ever had was his old Austin van. (about 30hp IIRC )

[kambites]

I find 200-250bhp/tonne about the limit at which the power starts to detract from the driving experience on the road. It'll be different for every person, though.

[wiliferus]

GetCarter said:

kambites said:

I find 200-250bhp/tonne about the limit at which the power starts to detract from the driving experience on the road. It'll be different for every person, though.

Again... I'd point out, BHP is completely irrelevant until you factor the weight of the car.

Which is why he used BHP per tonne figures?

[DanielSan]

GetCarter said:

Again... I'd point out, BHP is completely irrelevant until you factor the weight of the car.

That's why he have a bhp per tonne figure.

[Vincefox]

Personal taste, but my car's 320 bhp and not proper heavy. I think i'd like it to be 400 but perhaps that's just because it's a significant, higher round figure.

Most of the time i can't get anywhere near using the power i have, but it's nice feeling like i'm not straining the car.

[GetCarter]

DanielSan said:

GetCarter said:

Again... I'd point out, BHP is completely irrelevant until you factor the weight of the car.

That's why he have a bhp per tonne figure.

Deleted reply as I saw per tonne. Apols.

But I think 500 per tonne works well

[PhillipM]

You'd struggle to use anything over 100bhp/tonne at full chat over most UK roads tbh.

Mind, that's not to say the odd blast with more ponies when available isn't fun...

[aww999]

300bhp/tonne with frantically short gearing and no windscreen makes for instant overtaking, great acceleration, but so much wind blast that sustaining >100mph becomes difficult.

[heebeegeetee]

I think figures hardly come into it. I'd say it's got far more to do with when, where and what are the conditions like?

[GetCarter]

PhillipM said:

You'd struggle to use anything over 100bhp/tonne at full chat over most UK roads tbh.

You need to get out more mate

[PhillipM]

GetCarter said:

You need to get out more mate

Not really, that's what my 306 had and I had to back off often enough in that unless you wanted to spend a few years picking up soap.