MPG - Cruise Control or Speedlimiter?

[Bowruss]

What do people think? Better mpg if the speedlimiter is used or if the cruise control is used?

Say - m/way trip at constant indicated 75 mph: speedl. or cruisec.?

Would terrain and traffic make a difference?

Russ

 

[television]

What do people think? Better mpg if the speedlimiter is used or if the cruise control is used?

Say - m/way trip at constant indicated 75 mph: speedl. or cruisec.?

Would terrain and traffic make a difference?

Russ

Well the limiter would not come into play,it would just mean that you could not drive over that speed.

With the cruise,it is often said that going up a long incline it will change gear to mantain the set speed, where as if you were not in cruise you would back off a touch to prevent change down.

Malcolm

 

[Bowruss]

I see your point about the speedl. Malcolm.

I was thinking about just sitting with my foot planted down so that the car got to 75 and stayed there.

I suppose I'm really asking how the two systems work. I assumed that the speedl. recognises the max speed and prevents the engine from producing more power. The cruisec. maybe fluctuates power to maintain the set speed.

But which is the more economical?

Russ

 

[Blobcat]

The most economical is driving yourself, that way you don't accelerate on the uphill sections as the cruise control does. However that is unbelievably tedious and for the sake of 0.? mpg is it worth it. I set the cruise whenever I can and use the speedlimiter where cruise is not possible. I don't do it for economy I do it for the licence saving
In my signature you can see the economy of my car for the last 100 hrs of running. It is lower than previous as I have not been doing quite as many long journeys. Previously >40mpg for 100hrs.

 

[slim_boy_fat]

The most economical is driving yourself

Agreed,

You can back off on uphill sections and let the car run faster on downhills if you take control. Results in the best MPG

Cruise is much more relaxing however!!!

 

[jberks]

Agreed,

You can back off on uphill sections and let the car run faster on downhills if you take control. Results in the best MPG

Cruise is much more relaxing however!!!

absolutely - the cruise is about the worst for ecomonly in the UK. In flat clear motorways it's probably excellent but it can't anticipate (even the distronic), will accelerate to maintain speed uphill and won't take advantage of the downhill sections.
My best economy (48mpg) was achieved by letting it slow to 60 uphill and pick up on the way back down over 120 miles. Damn tedious though.

 

[television]

absolutely - the cruise is about the worst for ecomonly in the UK. In flat clear motorways it's probably excellent but it can't anticipate (even the distronic), will accelerate to maintain speed uphill and won't take advantage of the downhill sections.
My best economy (48mpg) was achieved by letting it slow to 60 uphill and pick up on the way back down over 120 miles. Damn tedious though.

All correct unless you have so much power that the car does not notice an incline. But then if you are running a 600 V12 you would not care,so that cancells out what I have just said


Malcolm

 

[Ade W124]

the cruise control on my CE is hilarious, if you have to slow down below 60 with it set at 80, when you switch it back on it kicks down and screams back up to 80 as if you'd floored the throttle.. hardly economical..

It also hunts/surges a bit which is annoying (could do with a good clean no doubt..)

Ade

 

[Bowruss]

I'm sure you're all right in what you say about self-driving being the best for economy. I try to do this whenever the mood takes me but I do like all the aids we get with our cars and, like Blobcat, I use them whenever I can.

My post was really just to explore if there's any mpg difference between the speedl. and the cruisec. in certain driving situations such as m/way at constant 75 mph.

Thinking about a bit more, I wonder if there is no logical reason why there should be a difference in terms of mpg. After all, the cruisec. keeps puting in power when it senses a speed drop and speedl. must do the same - if you keep your foot planted (which I suppose was not how MB intended it to be used). Also, I suppose that neither of them will take advantage of a long downhill section as they will both want to reduce power.

Just another thought. My previous car was a Passat with cruisec. but no speedl. I got into a regular habit of using the cruisec. whnever I could to keep to speedlimits - in town traffic as well as long trips. The slight drawback was that I had to reset it every time the brakes were used. The great thing about the MB's speedl. is that there's no resetting in stop/slow/start driving in traffic.

I reckon I just another well-pleased MB owner!

Russ.

 

[television]

There limiter is nothing like the cruise control. With the limiter the car will not go over the speed set,if you take your foot off the throtle, the car will stop, unlike cruise where you can take your feet away once set, until you touch the brake.

Malcolm

 

[Dave's E55 AMG]

Cruise control is very difficult to use these days, the only opportunity seems to be in the middle of the night when the motorways are reasonably clear.

 

[Flying Scot]

Cruise control is very difficult to use these days, the only opportunity seems to be in the middle of the night when the motorways are reasonably clear.

YES!!! an AMG55 and 32mph average speed and 20 MPG are you sure you have the right car

 

[daveenty]

YES!!! an AMG55 and 32mph average speed and 20 MPG are you sure you have the right car

Mine is practically the same at the moment. It's the getting to the mph which is the fun bit with them

 

[hexflyer]

I use cruise control as often as possible, if you can anticipate the traffic flow ahead you can use the +and- control on the stalk to adjust your speed, when the traffic slows a bit on the motorway then clears up, use your right foot to gently accelerate to your previously set speed and press 'resume' that stops the cruise control giving you rocket acceleration!

I've driven mine on long journeys under manual control and cruise control both at 80mph (which seems to be the unofficial motorway speed limit) and very little difference in MPG we're talking + or - 1-2mpg hardly worth looking at!

I find cruise control very useful whilst driving through the average speed camera areas (M1 luton etc) it looks like we're going to see alot more of these as well!