Cruise Control Adjustment

I have to ask... why would you want to engage cc as such low speeds?

 

I have a 2012 v3 station wagon, my cruise control always works at 24 MPH, I can sometimes get 23 MPH but it is way too much work.

 

I see, thanks.

 

I'd like to ask the opposite Q. I, too, have a couple of roads where I need to go 25. Why do they limit the lower speed at all? Why is it a problem to allow any speed, even 5mph? I hate the seemingly arbitrary limitations manufacturers put on their products, such as not displaying actual tire pressure instead of just a low pressure warning, "codes" instead of plain language interpretations, and the ever-unpopular navigation lockout while moving.

Grrrr.

Richard

 

Somewhere along the line they must have deemed it a safety issue. But it beats me.

 

There may be a technical reason why cruise control doesn't work well at slow speeds. Decades ago, cruise control used two magnets epoxy glued to the drive shaft and a sensor then determined how fast the drive shaft was turning by measureing the pulses from the magnets. Cruise control simply adjusted the engine speed to keep the pulses coming at the same rate. A faster turning drive shaft would cause the magnets to give a better defined pulse and thus better speed resolution. Also, any slop in the drivetrain would be more noticable at slow speeds possibly causing eratic engine acceleration and deceleration. Of course, modern technology should allow lower speed settings with the cruise control. I'd like to see a lower limit of at least 20 mph. That's because most school zones have a 20 mph limit and in my neighborhood the cops have been known to issue zillion dollar tickets for doing 21 mph. It'd be a lot safer using cruise control set to 20 mph so that I can keep my eyes on the road and watch for children. Right now, my Prius v can only be set as low as 25 mph, so I can't use it in a school zone and have to keep my eyes glued to the speedometer reading.

 

Blamy – Hello, from the Space Coast. The minimum set point on my my 2012 Pv5 Petrol Warfighter is 25 MPH/40 KPH. I see that you bought your Pv5 in August 2012. I purchased mine in December 2011. There are approximately nine months difference in factory production line Build Dates between our v (vees).

25 MPH = 40 KPH and 28 MPH = 45 KPM. Think metric. Maybe for some mysterious reason known only to Toyota, they raised the minimum ECC enabling speed by 5 KPH (3 MPH).

I seriously doubt that this ECC Set Point is dealer adjustable.

Like n0na, “I'd like to see a lower limit of at least 20 mph… because most school zones have a 20 mph limit and in my neighborhood the cops have been known to issue zillion dollar tickets for doing 21 mph. It'd be a lot safer using cruise control set to 20 mph so that I can keep my eyes on the road and watch for children.” The Gendarmerie in my small seaside bedroom community town “live” off the revenue from traffic violations. They, too, issue speeding tickets for doing 1 MPH over the 20 MPH School Zone Speed Limit.

 

I'm sure cruise control is now a software PID controller whose input is speed to at least three decimal places. Even so, very fine control of vehicle speed is somewhat more difficult at slow speeds simply because the difference between, say, 10 and 11 mph is a much greater percentage of vehicle speed than is 64 and 65. So there is no doubt some low speed at which a cutoff is necessary. But certainly 20 or 25 isn't it! While we're busy redesigning cruise control, why not display the actual set speed instead of forcing the driver to keep pushing the button up and down until he finally gets it right?

(Aside: Hey, n0na - Shouldn't your member category be "King of the Road"?)

Richard

 

My Prius v (wagon) with Adv. Tech. Pkg. and Dynamic Radar Cruise Control shows the set speed. It is a nice new feature that Toyota might add to other Prius lines.

Ref page233 here; http://www.toyota.com/t3Portal/document/om/OM47674U/pdf/sec_02-04.pdf

 

How about the speed that is displayed.....it's 10% or more higher than the actual speed.
I used a V-Checker to check the speed from the OBD2-port.
It displayed the right speed (checked with GPS) but the speedometer gives way higher numbers.
Does Toyota want us to think we are very fuel efficient @ 120 km/h, while we are only doing less than 110 km/h?

Modern cars don't need a margin of error in the speedometer. I just want to know what speed I am driving....not what mr. Toyota wants me to believe.....

 

Well.....my 2011 Prius 3 Executive (with adaptive cruise control and PCS) displays the set speed in the display of the ACC where you can see if the car "sees" a car in front of your car.
That model/version debuted in 2009.

http://www.cleanmpg.com/forums/showthread.php?t=42786

 

FWIW, on quite a few Honda's we've had the low speed limit for cruise control was 25 km per hour, roughly 15 mph.