Minimum speed and power required for a daily driver in 2024

[kevins]

I always found the vehicle that everybody gave me loads of room on was   the  battered white Transit with a tow bar we had at work,

Loaded it probably had a worse power to weight ratio than a 2CV.

[catsinthewelder]

I don't feel that I need lots of power, my 1.6TD Focus is perfectly adequate once it's moving.  The issue is usually the dim witted traction control cutting most of the horses out of the equation when you're trying to leave a junction quickly!

The Fake Harley could do with a little more power.  I have to plan routes that avoid steep hills which is inconvenient when I live on top of one.

[PhilA]

Best long distance vehicle I owned had 265 hp/ton and that was primarily because it chewed up miles at 70 like it was tootling along at 25. More than enough grunt to get where you wanted to if the mood took you, too. Did 32mpg at 70 also on average. 

Despite that, I racked up 135k in a car with 68 hp/ton, many of those motorway miles. Driving at speed wasn't a problem but that speed was very nearly top whack for the car so you were hard on the throttle and high up the rev range all the time. It also did about 30mpg at 70.

The Pontiac is about the same at 66 hp/ton but the engine is significantly less flexible so long range, high speed (60) becomes a chore. Forget overtaking anybody unless they have fallen asleep or are unlikely to sneeze and shift their foot on the throttle as you go to pass. 

 

Power per ton needs more factors than simply that, but 100/ton on up generally means you're low geared enough to not be screaming along at highway speeds, making the journey much more relaxed in general. And then, when some hole decides they want to give you grief you have a choice of actions.

The more GT the car (and I don't mean the 80's meaning) the better a highway machine it tends to be.

 

Phil

[Metal Guru]

Everyone seems to be forgetting you only get max power ( which everyone says their car has), at ~6000rpm and no one drives around at 6000rpm ( well I know a couple of pensioners that do but that’s a different matter).

So cruising down the motorway at 2500rpm you’re getting about half that.

Also In sure I’m not the only one who remembers when 100bhp was considered pretty impressive. My Dad had a couple of 2litre Cortinas , I think they were 98bhp and felt fast, and then got a 2.3 which had a massive 116bhp. 3 litre Capris only had about 140, as did the 3.5l Rover. The original mk1 Golf GTi had 110.

[TrabbieRonnie]

  On 31/03/2024 at 11:49, Metal Guru said:

Everyone seems to be forgetting you only get max power ( which everyone says their car has), at ~6000rpm and no one drives around at 6000rpm ( well I know a couple of pensioners that do but that’s a different matter).

So cruising down the motorway at 2500rpm you’re getting about half that.

Also In sure I’m not the only one who remembers when 100bhp was considered pretty impressive. My Dad had a couple of 2litre Cortinas , I think they were 98bhp and felt fast, and then got a 2.3 which had a massive 116bhp. 3 litre Capris only had about 140, as did the 3.5l Rover. The original mk1 Golf GTi had 110.

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I don't think anyone's forgotten that at all, it's just a yardstick we can use for what a given car/engine combo can do comfortably.

I do remember my Dad putting a 1600 in our 1300 Escort estate and the thing bloody flying afterwards... same thing when he put the 2 litre lump in our 1600cc Sierra.  Weight though, that's the killer for our more modern motors.

 

[SiC]

  On 31/03/2024 at 11:49, Metal Guru said:

Everyone seems to be forgetting you only get max power ( which everyone says their car has), at ~6000rpm and no one drives around at 6000rpm ( well I know a couple of pensioners that do but that’s a different matter).

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That's because BHP is a function of torque and rpm. 

BHP = Torque × RPM / 5252

Modern turbo engines (both petrol and diesels) have a very flat torque curve from low down. So you get plenty of urge low down where it's useful.

E.g. this VAG 1.5TSI as an example (from VAG training material)

Because BHP is a function of torque and rpm, the flat torque curve gives that linear bhp line. However it means you can boot low down and still have plenty of power without having to drop a few gears to get the acceleration out of it. 

Bhp/tonne is still useful as it gives a rough indication of performance.