V70: General Reasonable fuel consumption?

[yostumpy]

Originally Posted by Pidgeonpost

Slightly off-topic, but is it possible to shift from 'D' to 'N' and coast, then re-engage 'D'? Yes, I know it's frowned on for losing engine-braking and various other reasons, but is it possible or will the transmission go into self-destruct mode?

I did it all the time, was a bit wary first time, at 30 mph, but have popped into N at 60mph and coasted down hill, reacting 80 mph, then back into D at about 50 mph. But , tbh, I don’t bother now. The thing is, at anything over 40 ish, there is virtually NO engine braking, so a recent trip down the same hill, with foot feathering the go pedal, it stayed below 70 mph, and sat on 99mpg. Ditto at roundabouts etc, the lack of deceleration with the auto, might account for the brakes wearing out quicker than other cars, as it’s difficult to judge junctions etc, when the thing won’t slow down.

[Pidgeonpost]

Thanks. There are a number of routes that I use regularly where there are quite long gentle downhill sections of a mile or two where I regularly knock our other car into neutral. There's a temptation to do the same with the V70 auto. I've resisted so far, but old habits die hard.

[SnineT]

Lads there's a warning in the car manuals to say don't tow the car at over 20 mph usually so I wouldn't advise anyone coast an automatic unless it's a dual clutch and even then I'm not sure it's ok or whether the car does it automatically anyway.

[yostumpy]

Originally Posted by Pidgeonpost

Thanks. There are a number of routes that I use regularly where there are quite long gentle downhill sections of a mile or two where I regularly knock our other car into neutral. There's a temptation to do the same with the V70 auto. I've resisted so far, but old habits die hard.

Try it, it does feel good to waft along, I've been doing it for over a year, but as I say, there is so little engine braking, but you could...

at brow of the hill, quick 1-2 sec squirt to give you a bit more speed, then almost use your big toe only, just to feather the pedal, and you'll maintain speed, and read 99.9mpg. Driving this car in socks, does wonders for mpg, even though it's probably illegal.

I always knock a manual into neutral , where ever I can. I've had 35 mpg (actual) from my 1976 VW 2 ltr aircooled camper on a run back from a festival, (with a tailwind) avg for these is around 22mpg.

[apersson850]

Selecting manual when driving has no purpose. The engine will consume fuel all the time, to maintain idling while you coast. If you instead just let go of the pedal, it will consume nothing as long as the car's speed will keep the engine above 1500 r/min or so.
So this is pointless, and has been since the electronic fuel injection systems were introduced. The cut-off at released accelerator pedal was present already in Bosch D-Jetronic, introduced in 1967.

The towing restriction has nothing to do with coasting in neutral. The towing restriction comes from the fact that the gearbox gets its lubrication from the oil pump, and that's driven by the engine. As the engine is still rotating in this case, you're fine. It's different when towing, since then the only movement in the gearbox comes from the back, so to speak, and there's no oilpump there.

[monkeh]

Originally Posted by apersson850

Selecting manual when driving has no purpose. The engine will consume fuel all the time, to maintain idling while you coast. If you instead just let go of the pedal, it will consume nothing as long as the car's speed will keep the engine above 1500 r/min or so.
So this is pointless, and has been since the electronic fuel injection systems were introduced. The cut-off at released accelerator pedal was present already in Bosch D-Jetronic, introduced in 1967.

The towing restriction has nothing to do with coasting in neutral. The towing restriction comes from the fact that the gearbox gets its lubrication from the oil pump, and that's driven by the engine. As the engine is still rotating in this case, you're fine. It's different when towing, since then the only movement in the gearbox comes from the back, so to speak, and there's no oilpump there.

^This

When you let off the throttle, Injectors switch off.
When you idle, you use fuel...
Depends on the autobox manufacturer- Some run the fluid pump in neutral, some dont.
On my Ram, I know to cool down the autobox fluid, I can idle in neutral, because the pump still pumps. I'm not sure about the drivability of leaving the car in neutral.

Breaking downwith automatic cars in the past, I have always insisted on a flatbed recovery.

[griston64]

Originally Posted by yostumpy

Try it, it does feel good to waft along, I've been doing it for over a year, but as I say, there is so little engine braking, but you could...

at brow of the hill, quick 1-2 sec squirt to give you a bit more speed, then almost use your big toe only, just to feather the pedal, and you'll maintain speed, and read 99.9mpg. Driving this car in socks, does wonders for mpg, even though it's probably illegal.

I always knock a manual into neutral , where ever I can. I've had 35 mpg (actual) from my 1976 VW 2 ltr aircooled camper on a run back from a festival, (with a tailwind) avg for these is around 22mpg.

I drive barefoot all the time in summer.

[Pidgeonpost]

Some interesting insights there fellas, much appreciated. I'll have to try monitoring the rpm on some of these slow descents. But I think (hope) that you've answered the question about whether it's possible to shift into neutral on the move if I feel an urge to.

[FreshAir]

Originally Posted by griston64

I drive barefoot all the time in summer.

I did that once, had to do an emergency stop at one point.

The pain has not left my mind since (30 years ago) and it's not something I'll be repeating (driving without shoes).

[griston64]

Originally Posted by FreshAir

I did that once, had to do an emergency stop at one point.

The pain has not left my mind since (30 years ago) and it's not something I'll be repeating (driving without shoes).

I reckon that big auto brake pedal will be fine with bare tootsies for an emergency stop