I've noticed that when driving my PD105 diesel, while the engine is still cold if I upshift late, keeping revs between 2000 and 2500 but nowhere near full throttle, the fuel economy is better (The trip average economy passes 30mpg more quickly) than if I upshift at 2000 rpm, which is how I usually drive in urban traffic while the engine is warmed up. With the petrol engine I had previously, I couldn't find a situation where the fuel consumption was improved by using higher revs unless the engine was obviously labouring and heading for a stall. Has anyone else noticed this or am I imagining it? What other tips and guidelines do people have for getting the best efficiency out of their diesels? I presume also that behaviour like revving the engine to full power before the engine gets to temperature is very bad for its long term durability as well as fuel consumption?

I agree with your observations.

The PD105 is really easy engine to get great economy from imo. Just get to 5th as quickly as possible at speeds of 30mph and over. Pulling away from from lights for example in a thirty limit, get up to speed fast in 2nd and block change straight to 5th. On the motorway / dual carriageways, sitting on cruise control at 65 vs 70 - 75 really pays off. On a lot of journeys it will only add a couple of minutes.

The PD170 is more of a challenge to drive economically, but I'm learning to do it. I got 62mpg over my benchmark, parents house to home route yesterday. I think due to it being a 6 speed box and 16v engine, it's less about getting into top gear as fast as possible. The behaviour I've had to get out of, learnt from the PD105, is going straight for that top gear, especially up inclines. It's not efficient under load much under 2k rpm.

Edited 24 August, 200916 yr by wega3k

30mph in 5th :eek::eek::eek::eek::eek::eek::eek::eek:

Yes. A PD105 should do 30 in 5th on the level without labouring.

the answer is simple:-

more accelerator pressure = more fuel used

economic driving is all about driving in the correct gear and forward planning to make sure the brake pedal is used as little as possible. For example, when approaching a roundabout/junction etc, come off the throttle early and maximise the kinetic energy that the engine has already worked to produce rather than waste it by transferring it into heat energy (using the brakes). In short, let the car slow down under naturally as much as possible. By keeping it in gear the engine is turning itself.

the answer is simple:-

more accelerator pressure = more fuel used

economic driving is all about driving in the correct gear and forward planning to make sure the brake pedal is used as little as possible. For example, when approaching a roundabout/junction etc, come off the throttle early and maximise the kinetic energy that the engine has already worked to produce rather than waste it by transferring it into heat energy (using the brakes). In short, let the car slow down under naturally as much as possible. By keeping it in gear the engine is turning itself.

This is great advice and I frequently drive like this. I would also add that coming down the gearbox while allowing the engine to do the braking will enable you to be in the correct gear and add that little extra bit of braking without sacrificing economy. Using heel and toe technique you can lovely smooth downshifts

Yes. A PD105 should do 30 in 5th on the level without labouring.

Tried that in mine and its a big no no at that speed.40 was its min speed in 5th

I usually upchange between 2 - 2.5K also and when cold iam already getting readings of 48+ mpg and when normal temp it always reads 58 - 60 MPG and an actual of 57 MPG constantly around town that is.

Usually under light throttle i get these and hardly any boost but if i exercise it i get readings of 50 - 52 MPG.So still quite impressive

On 31000 miles now.

Hi boys ive the 105pd superb and I generally take it easy up the gears and on average I get 59 mph at 70:cool:

I get 59 mph at 70:cool:

Sounds like your speedo needs calibrating

My VR6 does 30 in 5th fine!

About the OPs observations, it'll have something to do with the efficiency of the engine, since you're now getting the turbo spinning more.

It's all about learning the car and engine.

Sounds like you're doing well on the economy front

I'd agree with the OP & Nick(Wega)'s observations ...

Plus you might want to have a browse through some of the commens in this thread too

Mpg???????? - BRISKODA - The Skoda Forums

My VR6 does 30 in 5th fine!

Probally does its much bigger engine.

Edited 25 August, 200916 yr by Taxi 219
Spelling

Tried that in mine and its a big no no at that speed.40 was its min speed in 5th

I usually upchange between 2 - 2.5K also and when cold iam already getting readings of 48+ mpg and when normal temp it always reads 58 - 60 MPG and an actual of 57 MPG constantly around town that is.

Usually under light throttle i get these and hardly any boost but if i exercise it i get readings of 50 - 52 MPG.So still quite impressive

On 31000 miles now.

Wait till you've got another 104k on that matey!

I never get much more than 400 till the reserve light comes on, sometimes 450 if im doing quite a bit of motorway driving. But then again im running 225/40/R18 tyres. Even with the map took off i achieve the same figures!

The majority of my driving is stop start driving through the outskirts of Sheffield, although i've been trying the 5th gear method with a full tank. It tends to cope better at 35-40mph in 5th on the flat.

I,ve found eversince they converted the clutch back to SMF it doesn,t like to go into 5th at low mph.From 40 mph upwards it seems ok.

Probally does its much bigger engine.

also different ratio, as he has 6 gears