Boring but mildly impressive

[vit4]

Big figures so what the hey

Me dad's been trying to see how diesel much he can get out of a tank. Crucifyingly boring, no acceleration, 30 in 5th gear etc so the car (Skoda Fabia 1.9tdi) is basically spending its whole day idling.

Paying off though... this is mpg around town. Hit 160 at one point . Would normally get ~400 miles from a tank, got over 700 from the last one. He gets fuel allowance which hasn't gone up at all despite the diesel prices, hence this

Viddy of trip comp

[Swifty Stig]

wow that impressive hehe

[Simbu]

30mph in 5th in a diesel? That really the most efficient gear for 30mph? My TDCi Focus is best off in 3rd at 30, will do it in 4th but would probably stall in 5th. Maybe the Fabia has very different gearing?

[mybrainhurts]

Those figures are as-they-happen numbers, rather than average, aren't they?

I get 650-ish miles from a tank on motorway runs in a Mondeo estate 130TDCi. 61mpg if I hold it between 50 and 70.

[vit4]

Simbu said:

30mph in 5th in a diesel? That really the most efficient gear for 30mph? My TDCi Focus is best off in 3rd at 30, will do it in 4th but would probably stall in 5th. Maybe the Fabia has very different gearing?

Runs at about 700rpm, tends to keep itself there without any throttle.

And Mybrainhurts, presume they're as-they-happen, but my guess is that if they're keeping relatively constant for mile after mile they'd essentially be averaging out? Not too hot on how it all works
Just s'pose above anything else it shows how changing driving can make huge differences. A bit like the Top Gear ones, but less staged

[mybrainhurts]

vit4 said:

And Mybrainhurts, presume they're as-they-happen, but my guess is that if they're keeping relatively constant for mile after mile they'd essentially be averaging out? Not too hot on how it all works

You can get such real time figures that dwindle to under 20 when a hill appears.

[stigmundfreud]

I've seen 58mpg on my v8 and that wasnt with dfco kicking in

it lasted about 3 seconds

[Mr.Jimbo]

mybrainhurts said:

vit4 said:

And Mybrainhurts, presume they're as-they-happen, but my guess is that if they're keeping relatively constant for mile after mile they'd essentially be averaging out? Not too hot on how it all works

You can get such real time figures that dwindle to under 20 when a hill appears.

My MPG swing-o-meter, which seems to be influenced by some sort of witchcraft, in the BMW sometimes sees 10MPG up a hill I somehow doubt it's the most accurate device ever created.

[chr15b]

Have seen my instant mpg display 2mpg when flooring it, means nothing though, full tank to full tank and do the math is the only acurate way

[slartibartfast]

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

[monthefish]

mybrainhurts said:

Those figures are as-they-happen numbers, rather than average, aren't they?

I get 650-ish miles from a tank on motorway runs in a Mondeo estate 130TDCi. 61mpg if I hold it between 50 and 70.

I can get 99.9mpg average in a V8 - I just reset the average mgp computer at the top of a hill. I can get this to last 30 seconds+ if the hill is big enough.

Sorry OP - not particularly impressive.

[chr15b]

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

[clarkey318is]

Mr.Jimbo said:

mybrainhurts said:

vit4 said:

And Mybrainhurts, presume they're as-they-happen, but my guess is that if they're keeping relatively constant for mile after mile they'd essentially be averaging out? Not too hot on how it all works

You can get such real time figures that dwindle to under 20 when a hill appears.

My MPG swing-o-meter, which seems to be influenced by some sort of witchcraft, in the BMW sometimes sees 10MPG up a hill I somehow doubt it's the most accurate device ever created.

I'm pretty sure mine is just connected to the accelerator backwards.

[annodomini2]

Had 92mpg(calculated not computer) on a real run out of the Clio.

Easily get 70 when out of town and not hooning it.

[Steameh]

Mr.Jimbo said:

mybrainhurts said:

vit4 said:

And Mybrainhurts, presume they're as-they-happen, but my guess is that if they're keeping relatively constant for mile after mile they'd essentially be averaging out? Not too hot on how it all works

You can get such real time figures that dwindle to under 20 when a hill appears.

My MPG swing-o-meter, which seems to be influenced by some sort of witchcraft, in the BMW sometimes sees 10MPG up a hill I somehow doubt it's the most accurate device ever created.

Ah yes, I often find myself staring in disbelief at my MPG needle in my BMW. 70mph, flat, cruise on 34mpg. 70mph slight incline, up the revs by about 200 cruise on, 15mpg.

[Platinum]

chr15b said:

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

The wheels turn the engine if you are in gear and off the throttle.

[monthefish]

Platinum said:

chr15b said:

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

The wheels turn the engine if you are in gear and off the throttle.

..and what is happening in the engines cylinders?

[annodomini2]

monthefish said:

Platinum said:

chr15b said:

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

The wheels turn the engine if you are in gear and off the throttle.

..and what is happening in the engines cylinders?

The engine management system is maintaining the idle, its not best for economy, you're better keeping it in the smooth running zone of the engine. it'll chug like crazy at that speed.

[Superhoop]

Platinum said:

chr15b said:

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

The wheels turn the engine if you are in gear and off the throttle.

Not when the engine drops to idle speed it doesn't. As others have said, when the throttle is closed and the engine speed is above idle, the injectors are switched off. As soon as the engine speed deops to idle speed, the injectors are switched on again to prevent it stalling....

Which is why a diesel will keep chugging along at idle with no throttle......

If you want proof, try pulling the car up to a stop on the brakes with the clutch out. A petrol would just stall - a diesel on the other hand will try its best to drive against the brakes

[slartibartfast]

monthefish said:

Platinum said:

chr15b said:

slartibartfast said:

I should imagine that it'll have a common rail diesel engine so you are best coasting where you can as IIRC it turns off the injections and hense uses no diesel so surely getting up to cruise and <james may> hyper driving <james may> would be better.

I tried being really gentle in my 1.9TDI 08 passat estate yesterday (105BHP version) when taking my kids back to the ex's and averaged 47mpg which is about 5 miles through town and 2 miles country and then back again.....yeah you can do it bu BOY is it boring!

I've heard this mentioned on top gear ages ago, i dont understand it, the engine is still ticking over (or turning over) therefore there must be combustion meaning a requirement for fuel?

The wheels turn the engine if you are in gear and off the throttle.

..and what is happening in the engines cylinders?

they're still sucking air in a compressing it but as far as I know/understand/guess not as much air due to idle so less chance of engine breaking, if I let me foot off the throttle when coasting at low speeds you can hear the diesel knock go.

I tried the same journey this afternoon where yesterday I was careful and got 47mpg but today I wasn't concentrating on fuel economy and got 40mpg so it just goes to show if you drive like an old fart you can save the planet......