Minimum HP requirement
 

Hey All,

I was cruising down a suburban road heading to work wondering how much power I would need in my car to keep the current speed (50 mph). It got me thinking about what other peoples' needs in a car would be. I know my father in would not consider anything under 160 hp.

Here people idolize Metros and the such, which must have around 60-80 hp.

I suppose I should really be talking about torque - which is why maybe the Prius doesn't "feel" slow when accelerating from a stop, and my Civic feels taxed when loaded with passengers and luggage.

What are your Friday afternoon ponderings on this matter?

You can use this nifty calculator Darin put together to calculate your HP requirement at speed. You can access it from clicking "tools" at the top of the page.

Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com


Horsepower requirements for cruising are pretty small.

Yes, I realize that. But what would one personally find acceptable in terms of "excess" or "passing" power? Sorry for the confusion.

Interesting question, "passing power" is quite often why people don't like to get smaller engined cars. I still pass people in my 127hp Tracker but it takes some planning and technique. The tailgate, pull over, and then nail it method doesn't work well with it.

At the speed I drive on highways I have roughly 55 to 65 hp available in 5th. When I want to pass I just mash it and it goooeeesss (relatively speaking...). So imho in a passenger car 60 hp right where you need it is plenty.

Geo's have 55 or 49hp, assuming you mean the 3cycl. I would think you could get by with 40hp or so at 55mph. Assuming it had a Cd of .32 or so, and was smallish.

Answer depends on weight & aerodynamics! (And to a certain extent the environment you drive in.)

The previous generation Smart Fortwo CDI (Canadian / Euro market) has 40 horsepower - and a worse (from the conventional perspective) power to weight ratio than a Geo Metro 3 cylinder car. I'd drive one!

Somewhat related thread:

http://ecomodder.com/forum/showthrea...good-5285.html

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Thanks for the feedback. So I am not alone - power compensates for lack of skill/inattention. Heh, makes me want to make a bumper sticker that goes something like this:

"Hybrids - Helping to get good mileage despite their drivers." Present company not included of course... :o

The world would be a much different place if power was inversely proportional to vehicle weight. Maybe then manufacturers would be more likely to build lightweight cars and trucks.

... but I digress. :D

My polo has a stonking 60hp, and it can out-gun 2 litre+ cars off the lights and due to the gearing @70 you massage the gas it will pick up effortlessly and shoot round passin 80+ quicker than most of the bigger cars I've driven in the states (v6 malibu/fusion/trailblazer/cobalt etc). alot of people mention power/weight ratio but personally for useability I prefer to look at torque/weight as a measur and maybe take a sneak at the gear spacing stats too!

I agree with the "diesel power". My parents still drive their 93 Passat TDI with 90 hp and it always is eager to pull. A torque/weight comparison would be interesting. Especially when looking from a performance and fuel economy point of view. TDI - FTW! :cool: