Retrofit cruise control

[Nick_J]

i really cant understand how it would worsen the economy!

When your using manual control, you speed up downhill (by a few mph) and you are using more momentum, but with cruise, it cuts the accelerator to keep it at "x" speed so you loose out on the "free" gravitational momentum (gravitational potential energy to be precise!)

This is also the same as when going up hill, you slow down a lil bit manually, but with cruise it opens the throttle more, using more fuel.

Also with cruise, definately for me, i stick it on at a slightly lower speed than what i might do on an open motorway where a ton is easy in manual!!!
This then will obviously give a better MPG, but its becuase your not actually cruising at the same speed as if you were manually controlling the throttle.

Hope this helps

 

[Ibiza 130 tdi]

When your using manual control, you speed up downhill (by a few mph) and you are using more momentum, but with cruise, it cuts the accelerator to keep it at "x" speed so you loose out on the "free" gravitational momentum (gravitational potential energy to be precise!)

This is also the same as when going up hill, you slow down a lil bit manually, but with cruise it opens the throttle more, using more fuel.

Also with cruise, definately for me, i stick it on at a slightly lower speed than what i might do on an open motorway where a ton is easy in manual!!!
This then will obviously give a better MPG, but its becuase your not actually cruising at the same speed as if you were manually controlling the throttle.

Hope this helps

That's exactly it!

Thanks for explaining for me!

 

[Nath.]

Well my cruise gets used for 90% of the time that I am behind the wheel and my mpg is fine and dandy and I arrive at work stress free, I find that I use my mirrors way more that without cruise as without it I have one eye on the speedo and the other looking out for the rozzers/scameras

Also to add, before I had cruise I managed to clock up two lots of totting up 12 points on my license and therefore two potential bans but with the cruise now for about 4.5 years and I have a clean license again

 

[mrcoyote]

When your using manual control, you speed up downhill (by a few mph) and you are using more momentum, but with cruise, it cuts the accelerator to keep it at "x" speed so you loose out on the "free" gravitational momentum (gravitational potential energy to be precise!)

Okay, being pedantic here...

Surely if it's cutting the throttle then it's using less fuel and hence conserving energy? Admittedly this energy could be converted into momentum by virtue of the gravitational pull on the car, but would the net result be more momentum gained or energy saved?

 

[mhill]

Okay, being pedantic here...

Surely if it's cutting the throttle then it's using less fuel and hence conserving energy? Admittedly this energy could be converted into momentum by virtue of the gravitational pull on the car, but would the net result be more momentum gained or energy saved?

Thats my thinking

 

[Nath.]

I find cruise gives me a psychological edge, when on the cruise and a boy racer passes me in his 1.1 saxo flat out at 82mph I just think to myself (hey you may have overtaken me mate but I didn't even have my foot on the gas)

 

[m0rk]

I find cruise gives me a psychological edge, when on the cruise and a boy racer passes me in his 1.1 saxo flat out at 82mph I just think to myself (hey you may have overtaken me mate but I didn't even have my foot on the gas)

or when you hit resume & accelerate down a sliproad quicker than the car behind

 

[Nath.]

or when you hit resume & accelerate down a sliproad quicker than the car behind

Yeah I was gonna say that too, out dragging pop pop cars with both feet on the carpet and one click of the finger on the resume button

 

[techie]

wow better get saving! how long does it take to fit?

Couple of hours.

 

[RichIbizaSport]

Anyone actually fitted this themselves DIY style (i dont expect techie wants to share his technique, i dont blame him!)

But since this is a forum and im sure theres plenty of people that want to give this a shot themselves (im not trying to undermine anyone) does anyone fancy listing part numbers, guides, hint, tips etc.

Or should i whack this in another thread?

 

[mrcoyote]

All the data for this has already been posted in another thread... (I think). The parts required took a bit of guesswork to begin with though, but it helps if you have a helpful parts guy at the dealer.

 

[RichIbizaSport]

EDIT - ok i didnt search very hard, turns out there plenty of threads on it:

http://www.seatcupra.net/forums/showthread.php?t=113506&highlight=cruise+control

 

[mrcoyote]

No they're completely wrong as the Ibiza stalks are more like the Polo ones rather than the Golf or Fabia.

 

[kane.cullen]

Hey techie, i live in wellingborough. What area do you work from? Is it northampton it self or a surrounding town/village? So just to confirm, it would cost £175 for seat parts and fitting of my pd 130 ibiza sport? Thanks

 

[bizzaboy]

I find cruise gives me a psychological edge, when on the cruise and a boy racer passes me in his 1.1 saxo flat out at 82mph I just think to myself (hey you may have overtaken me mate but I didn't even have my foot on the gas)

Yeah, but he (the boy racer) cant see that you're on cruise control though, can he?

I am happy to just cruise along at 70, making sure that I don't make any sudden movements with my right foot, that might raise the tone of my engine/exhaust, making the boy racer falsely believe that I am trying to race him!!

 

[Nick_J]

Okay, being pedantic here...

Surely if it's cutting the throttle then it's using less fuel and hence conserving energy? Admittedly this energy could be converted into momentum by virtue of the gravitational pull on the car, but would the net result be more momentum gained or energy saved?

From my understanding, the result is a loss of momentum when the cruise cuts the accelerator, meaning you loose out on 'Free' energy. Imagine this, going down a lets say 5% gradient, on manual at 60mph, say your foot is comfortable in one position on the accel and your happily increasing speed to 70mph.... youve gained 10mph..... If you notice this, you might reduce your accel foot slightly to go to 60mph over a period of a half a mile or so, or you might just leave your foot as it is and let the car regain to 60mph with the original throttle position.
Either way, your going faster due to momentum down the hill, this is 'free' energy.

If you have cruise, it will try and stay at 60, whether that means cutting the accel, then dapping it, cut abit , dab abit etc to keep to the 60. This effectively cancels out the free momentum you could gain by going down the hill.

Dont get me wrong, i had cruise retro fitted to my ibiza, I do use it when i want to stay at 70 if im not in a rush, or at 30 thru villages with speed cameras, its a useful device. But it is a trade off between using cruise and slightly reducing my economy!

Sorry this is a long winded reply!

 

[mgrays]

That link says it is not 2 part like the Fabia/Golf ..so yes it is a Polo stalk.

Cruise uses more fuel if you an analogue driver (i.e gently on/off, use momentum from hill to run you up next hill while backing off speed a little). However if you a digital driver (I'm amazed how many are...) then it saves you.. Digital drivers have 2 positions on the accelerator... full on .. full off .. as a passenger you feel the car surging all the time so no steady/slow movements of accelerator. Difference between those who should have a license... and those who should not

 

[Nick_J]

That link says it is not 2 part like the Fabia/Golf ..so yes it is a Polo stalk.

Cruise uses more fuel if you an analogue driver (i.e gently on/off, use momentum from hill to run you up next hill while backing off speed a little). However if you a digital driver (I'm amazed how many are...) then it saves you.. Digital drivers have 2 positions on the accelerator... full on .. full off .. as a passenger you feel the car surging all the time so no steady/slow movements of accelerator. Difference between those who should have a license... and those who should not

You explained what i was trying to say in a nutshell!!! Cheers!!!

 

[Nath.]

OK here's how it is with my CC

I have looked into what my cruise/MPG does over the last 2 days whilst on my way to swindon where as normally I am not even looking at my speedo as when on the CC I don't need to and can worry about other things

With CC set to 80MPH I was on a motorway with a long slight downhill slope (M4 westbound towards J15), my speed went up about 2-3MPH, looking at my instant MPG o-meter I noticed that on the way down the hill the best MPH I was getting was 350 MPG (for about 5 seconds). The instant MPG was considerably higher all the way down the hill. At the flat bit at the bottom of the hill the mpg gradually dropped back to normal

This tells me that my CC gave me a free ride down that hill in exactly the same way that I would/could have done it if I bothered my arse to concentrate on doing so

So today I was on the same bit of motorway and manually drove at 80 at the top of the hill and blended off of the throttle all the way down the hill so as to gain 3 MPH, In affect mimicking my CC. Guess what, I found exactly the same readings on the fuel computer

So IMO all those that reckon they can drive more economically without cruise they must be some sort of superhero and have way too much time on their hands to even bother trying

keeping your foot in the same position whilst going down a hill and getting more MPH for the same amount of throttle is a bit sad but lets not forget it is also speeding

Maybe we should be switching off the engine whilst going down hills and saving a bit more

I am thinking the answer to this bedate is as follows:- use the cruise and enjoy the stress free drive to work, or spend the hole time concentrating on the silly MPG o-meter and giving yourself a headache whilst nearly rear ending some poor sole because your not concentrating on the road ahead, *OH and getting 2.76MPG more over the course of a week driving to work*

 

[mgrays]

It is a little less black and white with respect to fuel economy .. but cheap shots are fun

1. At same even speed then analogue driver in manual = cruise control economy.. maybe a little better as they tend to mode 3 below with anticipation (mine overshots on big CC resumes speed differences .. chippped gives out too much torque compared to stock so calibration is wrong which wastes fuel)

2. With digital driver then cruise control is better and safer.. well until they start playing with their gaming console/crossword.

3. If you can feather and use a little less up hills and little momentum going down ..then you are not absolutely cruising but you will better the cruise control economy. Funnily the older analogue cruise controls had wider control windows (ie 5-6 mph on a 2002 Disco).. and so they tend to do this automatically.. now the totally digital VAG ones hold 1-2 mph but this is at expense of fuel but the gain of license. Sometimes think I want 2 settings.. one for economy.. one for sailing closer to the wind..