Gotta love Tdi economy

[gregozedobe]

PD, a few questions for you -

Are the fuel consumption figure calculated by the full tank to full tank method ? Figures from trip computers aren't always accurate.

Is the traffic and driving style the same ? To get the best economy out of a diesel requires a different driving technique (usually a lot less revs). Have you been guilty of enjoying the surge of torque in your Polo a little too often ?

The Polo is 200Kg heavier than your clio, and it uses fuel to move mass.

How many Kms have you done in your Polo so far ? It might (probably will) get better economy once it gets more than 15-20,000Km up.

Do you do lots of short trips where the engine is still warming up for much of the distance ? My TDI gets relatively poor economy for the first 10 Km of a trip, it seems to use a lot of fuel just to warm the engine up. Once it is properly warm the fuel consumption reduces significantly.

Stop-start traffic seems to drag my economy down a bit too, but flowing traffic is much better.

[Pumpe-Düse]

PD, a few questions for you -

Are the fuel consumption figure calculated by the full tank to full tank method ? Figures from trip computers aren't always accurate.

Is the traffic and driving style the same ? To get the best economy out of a diesel requires a different driving technique (usually a lot less revs). Have you been guilty of enjoying the surge of torque in your Polo a little too often ?

The Polo is 200Kg heavier than your clio, and it uses fuel to move mass.

How many Kms have you done in your Polo so far ? It might (probably will) get better economy once it gets more than 15-20,000Km up.

Do you do lots of short trips where the engine is still warming up for much of the distance ? My TDI gets relatively poor economy for the first 10 Km of a trip, it seems to use a lot of fuel just to warm the engine up. Once it is properly warm the fuel consumption reduces significantly.

Stop-start traffic seems to drag my economy down a bit too, but flowing traffic is much better.

The Polo 1.9 TDI does not have a trip computer, so it is the full tank to full tank method.

Traffic and driving style has not changed. Except maybe that to do certain overtaking manouvres I don't downshift, don't need to.

In the Clio (124kW @ 6250rpm, 200Nm @ 5400rpm, 7250rpm limit) I drove like this

1st-2nd = 3500rpm
2nd-3rd = 3200rpm
3rd-4th = 3200rpm
4th-5th = 80km/h

Cruising gears were 50km/h in 3rd, 60 & 70 in 4th, 80+ in 5th.

In the Polo (74kW @ 4000rpm, 240Nm @ 1800-2400rpm, 4500rpm redline)

1st-2nd = 2500rpm
2nd-3rd = 2200rpm
3rd-4th = 2200rpm
4th-5th = 80km/h

Same cruising gears as before.

Most of my driving is about 70% highway, 20% city. And no, I don't do short trips. My shortest average trip is 30km. Its at 3400km now, had it for 3.5 weeks or thereabouts.

Best consumption figure to date = 5.67L/100km, worst = 6.32L/100km. Last tank got me 5.82.

[Eureka]

Going from a 2001 RenaultSport Clio 172 (2.0 DOHC 16v petrol, 124kW 200Nm, 1035kg, 5sp manual) to my 2008 VW Polo 1.9 TDI (as everyone shold know, 1.9 SOHC 8v Diesel Turbo, 74kW 240Nm, 1222kg, 5sp manual)... with the Clio's old consumption figures (7.8-8.0/100km avg per tank) to this car's (5.67/100 best so far, 6.32/100 worst, average around the 6.0 mark) and the current price difference of 98 RON vs Diesel... it costs me roughly the same to run as the Clio did. In fact, if I were to be an avid watcher of the cheaper days with petrol, the Clio would be 50 cents cheaper (its nothing I know) a week to run.

Not quite what I imagined it would be like, and a fair bit off the little sticker in the window that said 5.0L/100km but hey, doesn't bother me.

Can't wait to do a highway trip in it, Clio's best on one of those (Sydney - Canberra - Sydney) was 5.2L/100km. I wonder if the Polo can better it...

Hmm, interesting. Not saying that you're wrong but I can't see how the fuel costs are similar on the figures you've quoted? If the Polo's average is 6.0 and the Clio's average is (say) 7.9 then...the Clio uses 31% more fuel than the Polo. Therefore, the cost of diesel would have to be 31% higher than PULP for the fuel costs to be the same. I'm unsure of the latest PULP price...but if we say it's $1.65 then diesel would have to be $2.16 for the fuel costs to be the same.

I've not given this too much thought so I could be wrong - but this is how it appears to me?

PS Love the choice of the Renault Clio Sport...thought about getting one once but couldn't find a good one locally.

[Pumpe-Düse]

Hmm, interesting. Not saying that you're wrong but I can't see how the fuel costs are similar on the figures you've quoted? If the Polo's average is 6.0 and the Clio's average is (say) 7.9 then...the Clio uses 31% more fuel than the Polo. Therefore, the cost of diesel would have to be 31% higher than PULP for the fuel costs to be the same. I'm unsure of the latest PULP price...but if we say it's $1.65 then diesel would have to be $2.16 for the fuel costs to be the same.

I've not given this too much thought so I could be wrong - but this is how it appears to me?

PS Love the choice of the Renault Clio Sport...thought about getting one once but couldn't find a good one locally.

I'm a little underwhelmed as far as the whole economy hype thing, depending on prices it can be from the same $ per week to run to $5 Polo's way. Not the difference I was expecting.

And yeah, the Clio 172 was awesome. If only its engine wasn't destroyed by a shoddy mechanic... (long story)

[gregozedobe]

Most of my driving is about 70% highway, 20% city. And no, I don't do short trips. My shortest average trip is 30km. Its at 3400km now, had it for 3.5 weeks or thereabouts.

Best consumption figure to date = 5.67L/100km, worst = 6.32L/100km. Last tank got me 5.82.

Hmmm, I'm not that familiar with Polos myself, but everything I've read (including Golfs and Octavias with the 1.9 TDI motor) suggest that under your driving conditions your fuel consumption should be a fair bit better than that, along the lines of 4-5 L/100Km, so I can understand your disappointment.

Your engine is still relatively new, and should improve with more Kms, but you don't usually get a huge increase over time.

Are there any other signs of something wrong ? (excessive oil usage, engine warms up very quickly or very slowly, black smoke from the exhaust under medium acceleration, engine running roughly, poor performance, DPF/engine light displaying etc.)

I think I'd be taking it back to the dealer and asking them to check on the engine anyway, as I get the feeling something may be not quite right.

[Pumpe-Düse]

Hmmm, I'm not that familiar with Polos myself, but everything I've read (including Golfs and Octavias with the 1.9 TDI motor) suggest that under your driving conditions your fuel consumption should be a fair bit better than that, along the lines of 4-5 L/100Km, so I can understand your disappointment.

Your engine is still relatively new, and should improve with more Kms, but you don't usually get a huge increase over time.

Are there any other signs of something wrong ? (excessive oil usage, engine warms up very quickly or very slowly, black smoke from the exhaust under medium acceleration, engine running roughly, poor performance, DPF/engine light displaying etc.)

I think I'd be taking it back to the dealer and asking them to check on the engine anyway, as I get the feeling something may be not quite right.

Engine doesn't make funny noises. So far as I know its not using any oil (better not be at 3400km old!), gets the odd bit of smoke from the exhaust under full throttle, performs well, doesn't run rough, no engine light... so I dunno?

[Preen59]

Engine doesn't make funny noises. So far as I know its not using any oil (better not be at 3400km old!), gets the odd bit of smoke from the exhaust under full throttle, performs well, doesn't run rough, no engine light... so I dunno?

Wait till you've done 10,000km or so. Your fuel economy will improve gradually up until about 10 thou. That's what i've found with my 07 Caddy 1.9TDI.

I've actually just 'chipped' it, with a TDI (Turbo Diesel International, i think is the name of the company) module, that i got from Guy Harding, while he was offloading some NLA stock for really cheap (cost me $225 to my workshop door!). I installed it monday last week.

I went from Orange to Sydney yesterday for the VWW cruise and averaged, on the trip down, 4.7L/100km. Mostly sitting on around 110km/h, aircon off apart from around 15 mins or so. I got 4.8 or so on the way home and around 5.1 average for the whole day. Which i think is pretty good considering there was 100k's or so of full throttle etc etc.

Before i chipped it i used to get around 5.4/5.5 average on a trip down and back to sydney.

So apart from my fuel economy info, the point is, yours should improve as the Caddy was similar when it was new.

Hope that helps, or is atleast interesting.

[Russ59]

I'm not sure if they filled the first tank right up from the dealership or not but I have just refilled the GT Sport for the 1st time and I am absolutely thrilled with the fuel economy. On my calculations not the computer it has averaged 6.97L / 100k's with a mixture of hwy and city driving. I haven't been thrashing it but there has still been a fair bit of spirited driving involved, one things for certain, if I'd been driving the XR6 the same way I would have been at the bowser a whole lot sooner and pumping the fuel in for a lot longer. And from what I've read so far it stands to get even better economy

[GoLfMan]

i just got 5.2L/100km out of my last tank on my chipped Polo TDI

woot for power and economy!

[Pumpe-Düse]

I just did an interesting drive... Sydney - Canberra - Sydney. With some driving (at night with no traffic) around Sydney and Canberra included. It did 4.94L/100km. My old Clio did 5.2L/100km on the exact same trip (I do it often).

Engine has 7200km on it now and seems to sit between 5.6-5.9L/100km combined if I drive like grandma all the time. Any time I do anything fun like a run down the Royal National Park or something... it jumps to the 6.3 mark for that tank.

The economy is *ok* but not as impressive as I had first thought (from browsing forums such as this one). Can't say I'm completley sold on the Diesel thing. Working out how much I spent weekly, the Polo sets me back about $5900/year on fuel. An LPG Falcon, worked out at 20L/100km (being pessimistic here, they do use less then that) would cost me $3800/year on fuel and be significantly faster and significantly cheaper to service.

Can't wait to get back into a petrol powered sports car. Though there is the odd Diesel car that I'd love to own... Audi R8 V12 TDI anybody?

[mr_walker]

This is an interesting read:

http://communityhosting.net/tdiclub/...p/Fuel_Economy

Cheers,

Walker

[PaulM]

Cheers Walker.

Some interesting info there - though the "breaking in" info contradicts VW's own manual. So who to believe? there are 2 definite schools of thought here - one is take first 1500k easy and then go for it (mine lol) while the other is namby pamby the engine til you die of old age

[mr_walker]

I know - the break in method debate has been done to death, and is over here. This is based on the Motoman method, which is here. Pick a method and go with it I say.

What I found interesting in the TDIClub article is that giving it a bootful around the 1750-1800 torque band is the most economical way to get up to speed. The link between cruising at low revs and EGR clogging your intake was also a new one for me.

[PaulM]

OK have done 4000K on my baby now - and I LOVE the economy. Whoever reckons or says it's imaginary are on something

My previous car - 2005 Magna VRX. 1 tank of fuel per week.
This baby - same K's, same driving, 1/4 tank for the week! So at this stage:

Magna to fill ~$90 x 4 = $360 per month
TDI to fill $95 x 1 = $90

$360 - 90 = $270
$270 x 12 = 3240 savings per year

Looks to be some savings there.....

[mikinoz]

I am getting near 800 a tank in the inner sydney cycle.

Going to be hard to go back to a petrol car really...