Cruise or right boot?

[Gafferbill]

Mr Parksy.........Hope you and Carol have a great holiday in Cornwall.

I bet your Sorento will return much better MPG than your Mitsubishi any how 🙂
All the large trucks now have cruise control and that combined with being limited to 56mph gives them the best economy.

 

[tadhgocuilleain]

WC. I agree with others yours is not working correctly.
If you dip the clutch and CC doesn't disengage your engine will tear itself to pieces.

I'm not so sure about that. I haven't checked it myself, but my brother said the cruise control on my father's Mercedes C-class is the same. I asked him if it revs when you clutch, but he said it doesn't. You clutch, change gear and when you release the clutch, it continues at the same speed.

 

[Hutch]

Sorry, didnt realise we were on about WC's car. My Vauxhalls CC would drop out on a gear change though. So I think no problem.

 

[WoodlandsCamper]

WC. I agree with others yours is not working correctly.
If you dip the clutch and CC doesn't disengage your engine will tear itself to pieces.

I'm not so sure about that. I haven't checked it myself, but my brother said the cruise control on my father's Mercedes C-class is the same. I asked him if it revs when you clutch, but he said it doesn't. You clutch, change gear and when you release the clutch, it continues at the same speed.

I've just looked at the User Manual and automatic deactivation of cruise control is triggered under one of eight criteria. The one covering our discussion is:
"The clutch pedal is depressed for a few seconds"
therefore changing gear normally takes less than 'a few seconds', so cruise control is not deactivated. I guess the ECU knows the clutch pedal has been depressed initially and therefore does NOT race the engine. I like the new method. 😉

 

[Martin24]

Hello Parksy,

We're very jealous of your Cornish holiday.

I'm going to be honest and say I've read your initial post and not the rest having just returned from the Motability Roadshow at Stonleigh on our way back from Hampshire.

When towing, neither of us use the cruise control as we prefer to feel in total control. Fine you're still in control some will say but that's how we feel and what we do.

On this week's solo trips we've done a mix of cruise right hand and right foot. Not fair to say which is cheaper but we managed 38.2 mpg which we don't think is too bad for a 2.5 twin turbo.

I probably use the cruise less than Jenny as my hands are full with my driving aids and have to let go to turn the cruise on.

 

[ProfJohnL]

My current Passat has the DSG box and CC.and i find CC very useful indeed. Most of my journeys now are local and involve 20, 30 40 and 50mph zones. The CC implementation in the Passat is quite handy as not only can to increase and decrease set speeds in as it can be increased and decreased in 1 mph steps, it also has 5 mph steps which means its easy to select a new speed to comply with the local speed limits.

The DSG box sorts out the gears as required, and I have noticed that it does seem to be load sensitive as it will change down a cog if the engine starts to be loaded before the the speed drops significantly.

Add to that the automatic brakes that hold the car if you come to a stop, it's as close to point and squirt driving as you can get. The in car MPG indication is wildly optimistic, but becasue most of my driving is on town roads its really difficult to be able to compare MPG for CC and right foot.

CC is a great asset especially for keeping to motorway road works average speed limits.

 

[KeefySher]

Over the past 30+ years of driving in countries all over the world and doing probably over 2 million miles in cars with cruise control, i use it all the time. It's become second nature

The early years were primarily American cars with auto boxes and armchairs. My first UK car with CC, in 1998, was a manual roadster with a straight 6 petrol lump, certainly helped economy when on long runs.

From those early CC where you manually controlled the CC, to my current car where you can use the various almost autonomous systems which leaves you to just steer the car, the CC has evolved.

In respect of towing a caravan, which is the relevant bit, I'm on my second tow car. They both have/ad the same 3 litre diesel engine. The last had a 7 speed autobox and the sat nag was linked to the CC. The current car has a 9 speed outbox and more autonomous systems I'll describe further on. They both have/ad Traffic Sign Assyst as its called that uses a camera in the windscreen to recognise speed limit signs and will if used match the speed to the limit automatically, just accelerates hard and decelerates equally as hard, so maybe not the most economic way of being driven. I don't use that when towing.

The CC on both have a 1mph flick function on the steering column lever for accelerate or decelerate, together with a 5 mpg increment as well. You can also use the lever manually in place of your right foot to control speed. The last car had no gear indicator. The new car displays the gear you are in. However at 60mph when towing it will not go into 9th as the engine speed is too low for the final gear. Solo it goes into 9th at about 63 mph. This is a function of the emissions regs to meet the targets by putting more cogs in the box, so any reduction in motorway limit as recently muted will actually increase emissions as 9 speed cars will not get into top at 60 mph.

The new car has a system called Distronic Plus that allows you to set the distance from the vehicle in front and maintain the distance up to a pre set speed. This is a radar based system with the big black solid badge in the grille. This is particularly useful when towing, I find. Solo it makes the journey more relaxing as I set the speed at the posted limit and orf we go. It's been interesting to try out various scenarios. I did the same journey a few times. Initially I did it at my previous car cruise speed in the new car, then with the system above and found time wise the journey overall was the same, and economy was far better at the lower speed. So I now set the system to the speed limit. So my behaviour has changed. Who says you can't teach an old dog new tricks!! 😛 😛

When towing on the motorway for example I set 60 mph. If i come up to a slower moving vehicle the car maintains the safe distance behind until I can find a space to pull right and overtake up to 60. Interestingly when solo and at 70, cars come racing up behind, overtake and invariably throttle off and drop their speed by up to 10 mph, which my car reacts to, then you accelerate again. It may be a macho thing about overtaking a big Merc with a fizz bang boy racer car 😛

This system also brakes the car automatically should I want it too, just a bit harder than I would if on manual control.

On the A303 at Sarum there is a speed camera. going westbound down the hill, the car tays at 70. others brake very hard as they see the camera. Eastbound lots of drivers race off from the Amesbury roundabout after invariably being in a queue past Stonehenge, go round the right / left switch and start the incline, then see the camera and brake hard losing all inertia for the big climb. I cruise past at the constant 70 and eat the hill with ease the gearbox dropping to 7th on the way.

Further advancement toward fully autonomous will bring calmer driving as you will basically travel in convoy at constant speed at constant spacing, which can only be a good thing. Or have i finally calmed down with age and find driving is not the fun it used to be? 😛 😛

 

[Parksy]

Thanks everyone for the advice and good wishes.
I used CC for most of my journey in light traffic It wasn't particularly frugal but made for a nice relaxing tow.

 

[Gabsgrandad]

My philosophy is why have automatics and cruise control then worry about odd few mpgs. that might be the difference. Best move I ever made to go to auto and cc.

 

[Dustydog]

My philosophy is why have automatics and cruise control then worry about odd few mpgs. that might be the difference. Best move I ever made to go to auto and cc.

Pete. I did it too , many years ago and have never looked back. B)

 

[Parksy]

I agree, I wasn't tired from driving down yesterday, but I have to go and fill up now :lol:

 

[ProfJohnL]

Thanks everyone for the advice and good wishes.
I used CC for most of my journey in light traffic It wasn't particularly frugal but made for a nice relaxing tow.

How do you know it wasnt frugal? unless you have benchmark of doing the same journey with the same outfit but not using CC, you have no comparitor. Unlike your old Pajero which had a big lazy engine, the new car may have to work disproportionately harder when towing, which will affect MPG more.

 

[Hutch]

Prof, .Parksey is experienced, he knows, dont look at negatives. If the tow was more relaxed then that is all the better. I find different areas need different driving styles. And as soon as I give a good gap betwen a truck and myself , on a good cruise, some Numpty tries to get in between,

 

[Dustydog]

His engine has moved 4.25 tons or so for a fair distance.
I suspect he may have achieved 22 mpg overall.
Not bad for a Sorento auto working hard.
Any more guesses. Sorry no milenco prizes.

 

[Hutch]

Thinking my Sante fe, pulling 1625kg. Max.
Ok , my guess for a round trip for Parksey, there and back, 27. Mpg. Lets see.
😛.

 

[Anseo]

Ok , my guess for a round trip for Parksey, there and back, 27. Mpg. Lets see.
😛

I was going to say 27 mpg, but since you got in first I will say 26 mpg 🙂

 

[Hutch]

When, we leave RMK, Royal Milton Keynes, to go to Dover with the van, we get 32 mpg. As soon as we get into Fance and hit the Northern hills the mpg drops to 25 ish. Last year over a 2500 trip to south of France and back, we recieved a 26 mpg, which I was happy with, Sante Fe and a " Heavy " Caoachman 560. . .

 

[ProfJohnL]

, dont look at negatives.

I don't understand why you should write that!

How can you know if something has changed unless you have a benchmark with which to compare it????

I fully agree with comfort and reduction of stress by using CC, and some people may think its worth a few MPG but Whilst I don't know Parksy personally he is a realist and he wants to know if CC is less frugal than boot on pedal but the only way he will be able to answer that point is to do some comparison runs.

Logic suggests cc will be poorer than a frugal right foot, but perhaps Parksy is not as frugal as he could be in which case cc might be better!

 

[otherclive]

Having used CC when I lived in Canada and Oz i found it to be very useful, but not to such great extent in UK. Our M ways are always busy until you get north of M6 Jn 36 and I find it much easier just using my right foot than having to continually keep switching, restoring or adjusting the speed in small increments. Even in road works with a 50 mph limit the car in front's definition of 50mph is invariably different to mine. If I had distance control too that might be an improvement but even so CC doesn't allow me to easy off when going downhill which I tend to do when towing until I am happy the car is in control of the caravan! Saving or not saving the odd litre of fuel isn't a real driver as I am now getting 32mpg towing which is the best for years and beats the Subaru 2.0 petrol's 24mpg so I can now afford the odd fill up with V Power or Ultimate.

 

[Parksy]

, dont look at negatives.

I don't understand why you should write that!

How can you know if something has changed unless you have a benchmark with which to compare it????

I fully agree with comfort and reduction of stress by using CC, and some people may think its worth a few MPG but Whilst I don't know Parksy personally he is a realist and he wants to know if CC is less frugal than boot on pedal but the only way he will be able to answer that point is to do some comparison runs.

Logic suggests cc will be poorer than a frugal right foot, but perhaps Parksy is not as frugal as he could be in which case cc might be better!

I haven't worked out the mpg for Saturday's tow from the West Midlands to St Ives, and to be honest I rarely check mpg but I know roughly how much each trip costs and how much fuel is remaining before filling up again.
The best comparison that I have are previous journeys to the same destination but with the Pajero.
Both 4x4 vehicles have the same fuel tank capacity and both are filled up at the start of the journey.
There's no direct comparison between the two vehicles but I know how much (or little) fuel remained at St Ives.
I wondered if the newer Sorrento would be more economical on cc than the 20 year old Pajero that we used on previous trips, but I'd say that there wasn't much difference in fuel spend.
I was able to use cc for most of our journey on Saturday morning because the southbound M5 was relatively quiet and the trip was relaxing and enjoyable.
The return trip might be somewhat different because we return on a Thursday and after leaving the A 30 the M5 is more of a steady climb overall.

 

[KeefySher]

, dont look at negatives.

I don't understand why you should write that!

How can you know if something has changed unless you have a benchmark with which to compare it????

I fully agree with comfort and reduction of stress by using CC, and some people may think its worth a few MPG but Whilst I don't know Parksy personally he is a realist and he wants to know if CC is less frugal than boot on pedal but the only way he will be able to answer that point is to do some comparison runs.

Logic suggests cc will be poorer than a frugal right foot, but perhaps Parksy is not as frugal as he could be in which case cc might be better!

I haven't worked out the mpg for Saturday's tow from the West Midlands to St Ives, and to be honest I rarely check mpg but I know roughly how much each trip costs and how much fuel is remaining before filling up again.
The best comparison that I have are previous journeys to the same destination but with the Pajero.
Both 4x4 vehicles have the same fuel tank capacity and both are filled up at the start of the journey.
There's no direct comparison between the two vehicles but I know how much (or little) fuel remained at St Ives.
I wondered if the newer Sorrento would be more economical on cc than the 20 year old Pajero that we used on previous trips, but I'd say that there wasn't much difference in fuel spend.
I was able to use cc for most of our journey on Saturday morning because the southbound M5 was relatively quiet and the trip was relaxing and enjoyable.
The return trip might be somewhat different because we return on a Thursday and after leaving the A 30 the M5 is more of a steady climb overall.

That reminds me of some standard mickey takes over the years:

Going north was always less economical and took longer as you were going uphill. 😛

The nearside of the car is always dirtier than the offside due to magnetic attraction created by the movement of air between the car and the kerb. That roads are cambered and all the detritus matter sits in the 'gulley' formed at the road edge and splashes the nearside has nothing whatsoever to do with the dirtier side. 😛

The car is connected to the white lines like on a scalelectrix track. 😛

Nowadays you'd get done for bullying or harassment if you put forward such joshing 😛

 

[ProfJohnL]

but even so CC doesn't allow me to easy off when going downhill which I tend to do when towing.....

Hello Clive

The comment makes me suspect you don't fully appreciate how CC works, CC does exactly what your foot does, if you need less or no throttle to maintain speed, just like you CC will reduce the throttle. So CC will automatically ease off when going down hill.

Do you mean you want to reduce speed when going down hill?, which is not the same as just lifting off.

That is easy enough to do with CC, simple disengage the control, its usually a flick of a switch, and its just as easy to re-engage when you want to return to the previous set speed.

 

[Dodger524]

but even so CC doesn't allow me to easy off when going downhill which I tend to do when towing.....

Hello Clive

The comment makes me suspect you don't fully appreciate how CC works, CC does exactly what your foot does, if you need less or no throttle to maintain speed, just like you CC will reduce the throttle. So CC will automatically ease off when going down hill.

Do you mean you want to reduce speed when going down hill?, which is not the same as just lifting off.

That is easy enough to do with CC, simple disengage the control, its usually a flick of a switch, and its just as easy to re-engage when you want to return to the previous set speed.

Further on the down hill thing. Cruise control is normally also connected to the cars brakes to maintain the set speed down hill.

 

[WoodlandsCamper]

Further on the down hill thing. Cruise control is normally also connected to the cars brakes to maintain the set speed down hill.

Ours doesn't apply brakes which is why we have to be careful in speed limits. Neither does the speed limiter apply brakes. Easy to trigger a speed camera when either is applied going down hill. 🙁

 

[Dustydog]

Further on the down hill thing. Cruise control is normally also connected to the cars brakes to maintain the set speed down hill.

Ours doesn't apply brakes which is why we have to be careful in speed limits. Neither does the speed limiter apply brakes. Easy to trigger a speed camera when either is applied going down hill. 🙁

Yes. Both our cars CC works as you describe. Neither applies the cars brakes nor does the limiter.
Personally and probably by habit I do disengage the CC manually on a steep long downhill . I feel and it is just a feeling that my manual override happens a while before the CC does. Maybe I can look further ahead than CC 😉 .