A cruise control system which has a numeric keypad on the steering wheel for desired speed entry.
You simply punch in the desired speed and press 'Enter' or 'set' or whatever the button would be called, and the vehicle would go to that speed at a smooth rate. There could be a + or - button to accelerate or decelerate the vehicle by one mile per hour (or a smaller amount).
There could also be a 'Maximum Speed' button which would allow you to drive as normal, pressing on the gas pedal, but would limit your maximum speed. Just don't forget to change it or deactivate it when you get onto the freeway.-- BJS, May 11 2007 I like it. Let me know when your ready to ship.-- jhomrighaus, May 12 2007 Sounds good.-- acurafan07, May 12 2007 That is so obviously the way to do it that no one ever thought of it. Another easy thing would be a button that would use the spedometer to toggle between displaying the set point and the current speed.-- Goesta Berling, May 12 2007 I think I'd prefer a programmable system, with maybe five quite large buttons on the dashboard that you could use while driving, but only be able to reprogramme the system while the car was stationary. The buttons would have displays on them showing the programmed-in preset speeds.
In the UK, you'd normally have the buttons set to 30mph, 40mph, 50mph, 60mph and 70mph. I don't know what you'd have them set to for other countries.
I like the Maximum Speed version - much preferable to the normal Minimum Speed cruise control - but being able to switch between the two would be good, too.-- Cosh i Pi, May 14 2007 Dangerous - what if I mistype?-- hippo, May 14 2007 I'd like it linked to sat-nav so that it sets itself to the speed limit of the road, maybe with a +10% option.-- marklar, May 14 2007 [hippo]
That's why I prefer the small number of big buttons, and only being able to reprogramme them when the vehicle's stopped. The idea of typing while driving bothers me!
Also, if it sets a maximum rather than a minimum, you don't instantly start accelerating willy-nilly if you hit the wrong button.-- Cosh i Pi, May 14 2007 I want a friend to text me his set speed and have that be my set speed.-- elhigh, May 14 2007 "The idea of typing while driving bothers me!" Teenagers do that all the time (at least where I live anyway).-- BJS, May 15 2007 Lots of things teenagers do bother me, [BJS]
Round here they periodically kill themselves doing such things, too. And sometimes kill other people, too.-- Cosh i Pi, May 15 2007 especially bad if your speedometer is bad to begin with-- aveek, May 15 2007 I was wondering about this the other day - how well calibrated are speedometers? Is one car's 80 mph another's 81 mph?
I like our car's approach - once it's in cruise control, you can nudge the cruising speed up or down a bit very easily.-- DrCurry, May 15 2007 I don't know what "...engines tend to bed in while doing fixed rev's" is supposed to mean.-- BJS, May 15 2007 Give me the existing buttons, but add in a display of the set point speed, either as a numerical display or as a pip on the speedometer face.-- Freefall, May 15 2007 The problem is not wearing in. At low RPMs under load you combine extreme loading with minimal oil pressure and that can lead to excess wear. When traveling at higher speeds(higher RPMs and lower loading(ie cruising on the highway) wear on the engine is minimal. During high speed runs (WOT) the loads on the crank are considerable and can wear on the bearings.
When an engine is broken in and over the course of its life the wear pattern on each bearing becomes matched to its respective journal. Once worn in they cannot be swapped or failure will occur in short order, the same applies to cam and valve train components.
The type of wear being discussed in the link is much more glacial than driving during a single session. It has more to do with not constantly driving only at idle over the life of the engine. An occasion trip on the highway or acceleration onto an on ramp more than satisfies this need.
Few cars would ever find themselves driven in such a way as to be subject to the sort of wear that is mentioned with the possible exceptions of vehicles such as a hearse or a parade car.
Contrary to your driving instructors comments driving at a steady speed is actually one of the best things you can do to an engine, Changes in RPMs cause surges in the loading on the engine and any change in loading results in wear.
The rough spot at 3500 RPMs most likely has more to do with a natural harmonic in the engine resulting in a larger amount of vibration than in other parts of the power band. Most engines are tuned to operate at normal speeds in areas where the run smoothly as vibration also equals wear.
A good way to look at this is to look at what happens to truck engines. An over the road truck that spends most of its operating life at a relatively constant High RPM can literally run for a half million miles with out too much trouble, a local delivery truck however experiences much heavier wear and may only last for half the number of miles as an equivalent OTR truck.-- jhomrighaus, May 16 2007 *I* like it, but it *IS* dangerous-ish to be typing stuff while driving. Worse than changing your radio station.
Put the buttons on the steering wheel and you're fine. [+]-- TahuNuva, Jan 05 2008 random, halfbakery