Fuel Misers

[Jody]

Slip my old 7 series into Sport and stand on the loud pedal and it would drop below 1 MPG for 5 seconds or so.

lol. I do like a 7 series. Which model did you have?

 

[swansonj]

I suspect are other variables in the hill climb scenario as well, it may well be a powerful diesel (or petrol for that matter) may be more efficient on hills than say an underpowered car.
Mine (astra J 1.6 petol) is really quite asthmatic and inclines are instantly felt in the economy figured.

I was reflecting on similar lines. The first and so far only car I have owned with an instantaneous mpg readout happens to be the smallest, lightest and lowest powered car I have owned (Citigo one litre). It makes the effects of gradients, winds etc much more obvious than a bigger car with a bigger engine. My belief is that the same principles apply to a bigger car though things like the actual optimum speed will be different. Having such a small and weak car however makes it much easier to see the effects of driving style.

 

[DaveReading]

Mine (astra J 1.6 petol) is really quite asthmatic and inclines are instantly felt in the economy figured.

I doubt that the car has been invented yet that burns no more fuel going uphill than on the flat.

 

[gbb]

I doubt that the car has been invented yet that burns no more fuel going uphill than on the flat.

Of course.....

 

[Mr Celine]

I suspect are other variables in the hill climb scenario as well, it may well be a powerful diesel (or petrol for that matter) may be more efficient on hills than say an underpowered car.
Mine (astra J 1.6 petol) is really quite asthmatic and inclines are instantly felt in the economy figured.

Petrol engines are generally at their most efficient with a fully open throttle and rpm around the point where the engine develops maximum torque.
(Efficiency in this case being kg fuel per kWh and not mpg, which is not actually a measure of efficiency).

 

[mustang1]

Does anyone inflate their tyres for economy ?
My 10 plate Astra had recommended pressures for normal, economy and heavy load conditions. IIRC, normal pressure was 30psi, economy was 36psi and heavy load was 40psi. I always run mine around 35psi. Some marginal extra wear will occur but my last fronts lasted 24k miles, so not wearing that much then.

Yup, tires are always inflated correctly. But not so much for economy as, well, i just like correctly inflated tires

 

[mustang1]

It's been said: I really don't think freewheeling in neutral is a safe idea, and certainly not turning off the ignition in most cars with steering locks!
stuff deleted
Best fuel saver ideas? (and really it's just common sense)
4. plan accordingly or use apps that can provide least trafficky routes or traffic controls
I'm all for being miserly with petrol, but really safety first. I'm sure there are other points I've missed.

I think some new cars set up their sat nav with option to guide you thru least hilly routes. I know BMW does that, may be some others do also.

 

[mustang1]

Wind resistance increases as a square of speed, regardless of whether you're on a level road or driving up a hill.

Need aero car like you get aero bikes.

 

[Drago]

lol. I do like a 7 series. Which model did you have?

E32 730iSE and E38 740i.

 

[mustang1]

Adaptive Cruise is an attempt to cope with moving traffic without disconnecting cruise control. However, as others note, it doesn't work well on roads with too many space invaders.

I think you can change the distance between your car and the one in front?

 

[mustang1]

There seems to be a sub-chat going on about 40 or 70 mph up a hill and/or slowing down.... something like that, i kinda fell asleep. BUT I gotta say it's rather irksome when on a motorway and people slow down going up a hill. I always figured it's because they're too scared o press the accelerator, a bit like when they pull out of a junction and are scared to accelerate like that's the wrong thing to do!

I say maintain your speed up the hill (sure, just use more fuel) and maintain speed down a hill (use less fuel, though I'm not suggesting the amount of fuel used up a hill will be negated by the amount of fuel going down a hill)... and I'm refering to motorways, north circular road, stuff like that.

 

[Bonefish Blues]

Anecdotally, my fuel consumption going up the M40 cutting on cruise at 70 roughly halves to high 20s on the instant consumption readout (my rough reading, since it varies with gradient). Going down also on cruise at 70 means indicated consumption of 99.9mpg, which is as high as it will go on my S60. It obviously takes exactly the same time to go up and down.

 

[Tim Hall]

I think you can change the distance between your car and the one in front?

You can on mine (skoda superb). I set the cruise control, tap in the destination into the sat nav, close my eyes and sleep.

 

[DaveReading]

BUT I gotta say it's rather irksome when on a motorway and people slow down going up a hill. I always figured it's because they're too scared o press the accelerator

Another explanation could be that their car just isn't powerful enough to maintain 70 mph when going uphill, and they haven't set out deliberately to annoy you.

 

[Jason]

Another explanation could be that their car just isn't powerful enough to maintain 70 mph when going uphill, and they haven't set out deliberately to annoy you.

they are annoying on the downhill sections however ,as most insist on doing 80mph within a mm of my bumper. I take great glee in holding the lane and scrubbing their gravity aided speed away ...... And waft effortlessly away on the next incline in my 3.0 Litre