Gotta love Tdi economy

[Preen59]

lyes i know diesels are slow, just like in le mans (audi/peugeot)

Quote worthy.

[gldgti]

Hi everyone

Reading all of your comments leaves me a little disappointed in my 2009 Caddy TDI's economy. The worst figure it returned was 8.1L/100kms, and the best is 7.4 which I got yesterday after a 800km trip from Adelaide to Penola and back (no a/c needed, no luggage, 1 x 60kg driver, good weather, virtually no other traffic, 110km/h - Cruise Control set, using BP Ultimate Diesel). The worst figure doesn't bother me as I know that my inner city stop-start driving is bad for economy (my previous Golf VR6 auto averaged around 11.5 for the same use). But I would have expected the rural driving to return a much better result. 7.4 doesn't even match the official URBAN cycle of 7.3 for the Caddy.

To reach the 5.3L/100km Official Extra-Urban figure for the Caddy I imagine I'd have to drive at 80km/h, downhill, with a tail wind! Are any other Caddy TDI manual drivers getting a better result?

I don't think the cruise control will do you any favours if your going up and down any hills. on a dead flat road, cruise might be better than the foot, but the brain is much better at being economical once hills come into play. (note, i've no idea if there is much in the way of hills i your area)

[Preen59]

I don't think the cruise control will do you any favours if your going up and down any hills. on a dead flat road, cruise might be better than the foot, but the brain is much better at being economical once hills come into play. (note, i've no idea if there is much in the way of hills i your area)

I beg to differ (With the VW cruise, some suck balls).

I find that the VW cruise control works tops and I am always going up and down hills on the highway where I live. The Mk4 and later cruise control is super sharp and very responsive. You don't get the delay you get with some other, older cruise control units.

When i was on the highway I was even using the cruise towing the car trailer, no issues what soever (except of course, down hills when I had to use the brakes).

[Preen59]

Is that the new CR version or the old 1.9 PD?

Preeny has one of the latter and says here that he has gotten 7.6l/100km average for Orange to Drysdale whilst towing a CAR TRAILER with the Mk1 on the back (and I don't doubt him for a moment)

I should mention that I am running a piggy back module (TDI- Turbo Diesel Innovations).. But this only accounts for ~5% better economy.

Don't be too concerned with your figures when the engine is new. They definitely use more fuel when they're tight. Wait until you've got about 10k on it and see what it's doing.

[kaanage]

I find that the VW cruise control works tops and I am always going up and down hills on the highway where I live. The Mk4 and later cruise control is super sharp and very responsive. You don't get the delay you get with some other, older cruise control units.

I think that gldgti is suggesting that a driver can get better economy than the cruise control as the driver can make small speed adjustments anticipating changes in the terrain (eg increase speed a bit downhill to help roll up the next hill while bleeding off a bit of speed) rather than just holding at a set speed all the time. This makes your fuel economy figures even more impressive.

Don't be too concerned with your figures when the engine is new. They definitely use more fuel when they're tight. Wait until you've got about 10k on it and see what it's doing.

I was disappointed with the fuel economy that I got with my 9N3 Polo TDi on a trip from Melbourne to Sydney and back when it was quite new (5.1l/100km actual). It seems to have improved as I've added mileage (now just over 10Mm).

Adding 2 stroke oil @ 200:1 seems to have helped too.

[rearrange]

Is that the new CR version or the old 1.9 PD?

Preeny has one of the latter and says here that he has gotten 7.6l/100km average for Orange to Drysdale whilst towing a CAR TRAILER with the Mk1 on the back (and I don't doubt him for a moment)

Mine is the old 1.9. It now has 9600kms on the clock. I did same Adelaide to Penola trip when the car was new at Easter last year and it returned 7.5L/100km with a passenger, lots of luggage, and lots of full acceleration overtaking all the slow moving holidaying breeder-wagons. I just can't believe this latest trip didn't beat that figure by more than 0.1L difference.

[rearrange]

I don't think the cruise control will do you any favours if your going up and down any hills. on a dead flat road, cruise might be better than the foot, but the brain is much better at being economical once hills come into play. (note, i've no idea if there is much in the way of hills i your area)

At least 600km of the 800km trip is flat roads. The Adelaide Hills are at one end, but they are hardly steep and 110km/h is easily maintained. I'm not expecting to set any economy records ... I'm not that sort of driver

[Preen59]

Gees mate you should be able to beat those numbers....

Re: cruise control..

I haven't found any improvement from using the foot over the cruise on the Caddy at all.

[William_Foster]

I have a 6R TDI Polo with DSG [With all the options, whichmakes it heavier than the standard] and I haven't really been overly impressedwith the fuel economy so far [I only use Caltex Vortex Diesel]. The brochurestates combined fuel consumption of 4.6, urban 5.5, and extra urban 4.0; so farI have done nearly 4,000kms and have average 6.0 in total; which includes fourtrips of 400+ kilometres and I have only seen a figure in the high 4's once ortwice.

I was told that once the motor bedded in a little the fuelperformance would improve, but there is no sign of it yet.
Yesterday I tried manual up shifting and using the DSG onthe downshifts on a 70+ kilometre journey on rural roads and found thatreturned a better than usual figure of 5.6; but till not brilliant. I havemucked around with cruise control and didn't find any noticeable difference inmy car.

Am I just being too picky to be expecting better fueleconomy?

[kaanage]

Sadly, your report is in line with the experiences of UK Polo 6R 66kW TDi owners. The issue seems to be the implementation of the DPF is poor so a lot of fuel is "wasted" due to frequent regeneration cycles. In addition, the low end torque seems to have been tuned out, probably to prevent driving below 1900rpm to avoid even more frequent regen cycles. This means that you don't get to drive in the diesels most economical rev range.

As a comparision, my 9N3 Polo TDi, which has the 1.9 PD engine with no DPF, can be driven off idle (literally - I often shift up at 1500rpm) and I get around 5.5l/100km around town and 4.5l/100km in the country. Preeny's Caddy uses the same engine