Improved fuel consumption after 20k?

[Gerrycan]

I have never recorded any improvement in the fuel consumption of any car I have owned from new, except maybe now I have an exception.
I have now done nearly 23k km in my Octy 3 1.4tsi manual wagon. Soon after purchase I established that cruising at our legal limit of 110 kph in favourably neutral conditions (no wind, above 20 deg C) that I got 5.7L/100.
My other datum point was what was the very best I could get in any gear, on the flat roads in urban Adelaide, and I thought that was 3.7L/100, usually in fifth gear at about 50 kph.

Now when I repeat the tests I cannot see any improvement on the 110 kph consumption but the low speed best has improved to about 3.4L/100 which might seem minor but still better than anything else I have achieved.

I have no intention of running around the countryside at 50 kph but the recent EV record set by a couple of Scandinavians in a Tesla managed something like 728km on a full charge which bettered the official 492km but they averaged only 40 kph.

Older diesels could easily managed 2.8L/100 (the legendary 100mpg) on an economy run but I am not sure what the modern ones would do now they have DPF technology interfering.

Another reference is the record for a tank set by a new Peugeot 308 with a 1.2tsi 3 cylinder engine and manual transmission which achieved 2.9L/100 on a closed circuit averaging about 55kph.

[woofy]

I got the best economy in my 2008 RS TFSI after the first 12mths/15k service. I had done all the running in the manual says (I notice for my new incoming RS the manual says to do even less now). I found much the same with my 2006 Mazda 6 as well. My 2011 Santa Fe which has the same diesel as the newer model ran pretty economical from day 1, but is a diesel.

[Gerrycan]

The Santa Fe diesel of that period probably does not have had DPF fitted, as mine did not. I'm not sure if the current one does, you would think it would have to now.

That was why I was confident that the VW 'dieselgate' situation would not apply in Australia because the emissions requirements were so low here that they were unlikely to have been contravened.
The problem for all modern diesel consumption claims is that it is unlikely that any manufacturer would allow the situation where a regen would take place in the middle of the test.

I found the Santa Fe an odd vehicle, nearly a very good thing but there were so many issues on mine that annoyed me.

[gadget007a]

I cant comment on the petrol engine as I have the Diesel, however subjectively i think the economy is better as I can readily achieve 900km per tank where as when I first got it I was getting low to mid 800's per tank. On the highway the motor sounds quieter / more relaxed.
As i said this is subjective the extra range could be from me knowing what to expect from the DSG and have altered my driving to suit, but I will say that I have noticed that the instantaneous consumption does seem more sensitive to minor changes in the inclination of the road than before.

[woofy]

No dpf, it's the R series. They had them when the engine first came in. Not really had any issues until I had a few things added to it, i.e. Head unit, LED screen and front parking sensors. Now it goes flat if you leave it 4+ days. Also hard plastic creaks are considered normal with it. I swear the engine has a ticking it didn't use to either, I can hear it a mile away when my wife's driving it down the street. The service advisor reckoned it had diesel knock in Jan which I thought didn't even happen on modern cars.

[Gerrycan]

I had a manual 1.9d diesel mk2 Octavia for about 6 years and 90k, loved it and thought I would never buy petrol again.
Easy to better 1000km with the a 55 litre tank on a run at whatever speed limit applied (GPS speed verified, the speedo was about 8% out).
The Mk3 came out and 1.4tsi guise was bigger lighter and much more sporty than the old diesel with similar claimed economy. Much cheaper than the new diesel version (only available in higher spec) so we plumped for it, but I knew that economy would not be as good as the diesel which turned out to be the case but there were a few surprises.

The old diesel would show consumption of .5L/hour at tickover which I thought was sensational but attributed it to the fact that diesel fuel has at least 10% greater calorific content than the equivalent amount of petrol, the higher compression ratio extracting greater energy content and the lower pumping losses as there was no throttle involved.
I was really surprised when I found that the 1.4tsi displayed an even lower static consumption of 0.4 to 0.5 L/hour. I am not really sure what the last petrol car I drove was (think it was a 2.4L Toyota Camry hire car) that showed static consumption but that was around 2.0L/hour.
I can only imagine the 1.4tsi achieves this with use of variable valves and the direct injection technology.

The other major change from the diesel was the relative lack of engine braking available but even compared to other small petrol engines it seems incredibly low. Again somehow pumping losses on the tsi engine seem to be radically reduced.

In short I reckon it took me about 2 months to re-learn how to drive the tsi economically especially the need to extend my anticipation of traffic movement way beyond that required by the diesel..
I reckon my consumption in the tsi is about 0.6L/100 worse than the diesel in most scenarios and overall but the tsi definitely requires a different skillset to achieve this.

[Gerrycan]

No dpf, it's the R series. They had them when the engine first came in. Not really had any issues until I had a few things added to it, i.e. Head unit, LED screen and front parking sensors. Now it goes flat if you leave it 4+ days. Also hard plastic creaks are considered normal with it. I swear the engine has a ticking it didn't use to either, I can hear it a mile away when my wife's driving it down the street. The service advisor reckoned it had diesel knock in Jan which I thought didn't even happen on modern cars.

My Santa Fe R pulled to the left, it went back 3 times and improved each time and on the fourth time I returned it they just said it was ok, normal, following road camber and just my imagination. Except on roads with an adverse camber it 'climbed' uphill and everyone else who drove it complained of the small but persistent tug to the left.
The throttle was very sensitive, and the AWD slow to react, so when you tried to turn into traffic it was easy to initiate inner wheel spin, then the electronic nannies cut power and you sat there seemingly waiting an eternity for negotiations to end and then she tucked up her skirts and sped up the road. Torque steer was quite bad in this situation too. Did not like the 6 speed slush box, I should have got the manual. Traffic indicators rarely self cancelled (tested and declared normal by the dealer). Ride on corrugated roads was poor. Wind noise at speed was high. Mostly functional vehicle but no fun to drive.
Economy was ok at 7.5L/100 overall for such a heavy machine, but it did require a bit of nursing to get that figure and I attribute most of that to the auto box.
Never had a ticking on mine but it did get quite a lot noisier over the 20k I had it, which was not what I expected.

The Mk2 Octavia was an absolute joy to drive, and not only by comparison with the Santa Fe. It even shrugged off the corrugated roads I struggled on with the supposed SUV.

[woofy]

I'm not going to lie, our Mk2 craps all over the Santa Fe, we even debated waiting for the soon to come out at the time 2012 Santa Fe as each version gets slightly better. But the feeling you describe as not quite there is pretty right. Hyundai owners might convince themselves they are driving a Japanese car at a cheaper price, but my 2006 Mazda 6 was far better in quality all around.

[bobski]

Both our Skoda's (2010 VRS and 2015 Superb TSI) averaged around 10% more than manufacturers claims. You could definitely hit manufacturer claims with careful driving and on long trips we often beat them. A bloody miracle if you ask me. After about 5000km though, their economy remained/s static.

OT.... I was underwhelmed by a top spec 2012 Santa Fe - at the time I was driving the VRS and it was hard to see why the Santa Fe was so expensive. I just never bought into the SUV/height thing, I'll take a Skoda wagon every day of the week for family duties.

[woofy]

We have only just realised how much longer our incoming Wagon is so height of the interior aside I'd be curious to see if the new Skoda has more boot space than the Santa Fe. My plan was to get the base model diesel Santa Fe, but we got the Elite for the same price. It would be nearly 10k more now so I wouldn't bother. Its handy to have the height in and about 4 yrs time the plan is to look hard at the Kodiak to replace it. If it was out already we may well have sold the Santa Fe. We got one because the Kluger was pretty spartan and no diesel was on offer, that and it was 10k more for the basic Kluger. The height has come in handy on some camping trips and its nice to not always have to worry about the concrete wheel stoppers in every carpark removing the front bumper for you. I'm 6'1 and loading is much nicer in the Santa Fe with the flat floor and it at hip height as well. I'll be much happier in our new RS when it turns up soon, I'll just have to watch my back loading down into it. The width of the Santa fe was a killer parking it, I had to get one whole side resprayed as no matter how I parked someone always managed to find a way to scratch it.

[spud75]

My 1.9tdi A3 with dpf will regularly see high 3l/100km on a highway run. Worst I ever got was adelaide to Melbourne with a stiff south easter the whole way fully loaded with a bike on the roof with a bike bra on it. (Read sail on the roof) stuck to posted speed limit and got 5l/100km. Sorry but VAG diesels with a dpf van get awesome economy. Same car unloaded started at moint lofty. Qas past norwood before avg consumption was above 2l/100km.

The mk 2 rs will easily do sub 5l/100km on a highway run but I havw seen rhat for a while sinve rhe roof racks and bike carriers stay on all the time. Generally hit 5.0 ok but seeing as always loaded just wont tip under. Need to get all the crap out of the car and off the roof and take for another spin. Still usually doing 800km per 50l tank.

[Gerrycan]

Wow! That is truly exceptional economy from the A3! About 25% better than I would get from the Mk2 in similar conditions.
Although Mt Lofty to Norwood I am surprised you used as much fuel as you did, maybe you had a very strong headwind

Roof racks and the like do not have half the detrimental effect on diesel vehicle consumption as they do on a petrol.
My bikes travel inside, and with minimal dismantling I can comfortably fit 3 people and 3 bikes with luggage.

[daljames]

My O3 Scout 135TDI will average about 5.3l/100kms on my commute from the nthn beaches to Balmain outside of peak times (shift worker). On regular trips to newcastle 4.8 ish (traffic dependent). Towing my caravan (1350kgs) i get around 9.3l/100km towing at 85km/h.

[GTR27]

I noticed an appreciable difference once over about 10,000k's Gerry. Like 0.5-0.6 L/100 in pretty much all conditions.

Anything over 100 really drops economy, even though the car could easily cruise at 140. On trips where traffic has dictated a 90kph speed, i've seen 4.9 L/100 with me, the wife, 2 kids a boot load of **** and a/c on. Same trip at 110 is about 5.7 L/100

[Gerrycan]

I noticed an appreciable difference once over about 10,000k's Gerry. Like 0.5-0.6 L/100 in pretty much all conditions.

Anything over 100 really drops economy, even though the car could easily cruise at 140. On trips where traffic has dictated a 90kph speed, i've seen 4.9 L/100 with me, the wife, 2 kids a boot load of **** and a/c on. Same trip at 110 is about 5.7 L/100

Most of the fuel usage figures for the 1.4tsi I have seen quoted have been remarkably consistent with what we are getting.

However my original posit was that running-in had ONLY made a noticeable improvement at low speed, and it was only remarkable insofar it was the first time I had seen any noticeable long-term improvement on any recent new car (diesel or petrol) I had operated.
This makes sense to me as low speed is where rolling resistance and friction loss improvements would show more readily. At high speed the friction improvements would be less apparent because of the relatively large effects of aerodynamic drag.