[Dazzler]

Just to throw a spanner in the works.....

On my current trip I've been using the "cruise" nearly all the time with much of it being in hilly country.
 
I drove from Lennox Head to Bundaberg today and averaged 4.7l/100km....and this included a bit of stop start driving through Brisbane. Much of the trip was also spent sitting at 110kph.... 

and some of that has been on two wheels   

from your signature "Four wheels move the body. Two wheels move the soul."

I wish....

I haven't been driving for economy on this trip and have been setting the speeds with the "cruise" according to the GPS so usually end up passing most cars out on dual carriageways... 
Here's hoping it's accurate otherwise I might not have my licence when I get home...

Yeah, I know where you are coming from.. I passed a speed camera on the way to Burnie the other day and i had the Cruise set as per the GPS. I looked at my speedo and it said 116 in a 110 zone but the GPS said 109 

I should be OK but only time will tell (I got flashed by someone coming the other way but was too late)

[mjt57]

There's a marked difference in the CC of diesel and petrol.

I have a Mazda Tribute, a 3l V6 and a 3sp auto with overdrive (probably the same box as in the Commodores and similar in function to the older i30 auto).

Anyway, because its torque and power are higher up and plenty of it once its revving, the CC on it is a PITA. It'll slow down on an incline, say from 110 to 100. Then it will kick back a gear and rev its way back to 115 kays or more before I have to tap the brake, slow back to 110 and re-engage CC.

If I take it out of overdrive by pressing the button on the end of the gear selector, it'll handle the inclines easier.

But the i30, well, it doesn't matter if it's climbing a cliff or driving down one, it'll maintain its set speed. It's as good as my old SS Commodore which could lock in a speed and stick to it. Having 240KW and 450 Nm on tap helped, though...

[mjt57]

An update on the fuel usage. Missus recorded 5.9 on her trip to work and back yesterday, same as my trip to work.

[Dazzler]

An update on the fuel usage. Missus recorded 5.9 on her trip to work and back yesterday, same as my trip to work.

 

I still think it will improve a bit more in time..

[Phil №❶]

An update on the fuel usage. Missus recorded 5.9 on her trip to work and back yesterday, same as my trip to work.

So we can't blame her then 

[mjt57]

In a 6 speed, 50km/h is where I'd be changing from 3rd to 4th. 1st gear I might get to 2700, but 2nd and 3rd are usually 2300-2500 when I change. Aiming to have the revs drop to about 1800 or so in the higher gear to be right at the bottom of the torque curve.

I took notice of my gear changes yesterday when I went for a drive. At 50 kays in 4th it's revving at around 1,500 rpm and the engine is straining badly. I'd change into 4th at around 60 kays where she's doing about 1,800 rpm.

50 kays in third she's revving at just under 2,000.

And I'm changing up at engine speeds around the 2,500-3000 rpm mark.

The only time that I bag it is when I have to accelerate to match higher speed roads when merging, or to simply keep up with traffic flow, particularly if I'm in the right lane. Usually on 70-80 km/h roads. Mind you, that's not all the time.

[mjt57]

So we can't blame her then

I wouldn't dare, anyway.

Her drive to work is a mixture of 70, 80 and 100 km/h roads before slowing back to 60 kays going into the town's CBD. The trip home is all 80 kays once outside of the town she's leaving (Morwell) with some traffic lights, IF she cops a red.

And after two days the trip computer still says 5.9l/100km.

I'm going to have to live with that, I fear. Still, it's cheaper than driving the Mazda which gets 14l/100km. And I fill it once a month.

[Phil №❶]

In our car I can feel the turbo kick in @ around 1800 rpm, so I guess if you're getting to 3k rpm occasionally, the turbo is really working and unless you need that power for safety / traffic reasons, I tend to stay out of that range if possible. At 80 k's my engine is a 2k rpm in 4th gear which I use to climb the 500m hill out of Adelaide. Once on top, I gently go to 110 which is about 2.5k rpm IIRC, so 3k rpm just doesn't happen.

3k rpm in any car in any other gear other than top gear is sucking in quite a deal of air & fuel. In a turbo car you're effectively force feeding air into the engine & the ecu inserts the appropriate amount of fuel. It has to cost more, which is why we all drive around in top gear.

Don't get me wrong, there are many who use that range and it is perfectly safe to do so, but it will affect the economy of the engine.

[rustynutz]

I suspect you're still driving a bit like you would a petrol engined car......
I guess old habits can be hard to break, especially if you're jumping back into a petrol powered car fairly regularly...

The only time I might change gears anywhere near 3000rpm is at the drag away from the lights....but that is usually while still in first gear, hit second and I then I try to make full use of the torque....

[Dazzler]

So we can't blame her then

I wouldn't dare, anyway.

Her drive to work is a mixture of 70, 80 and 100 km/h roads before slowing back to 60 kays going into the town's CBD. The trip home is all 80 kays once outside of the town she's leaving (Morwell) with some traffic lights, IF she cops a red.

And after two days the trip computer still says 5.9l/100km.

I'm going to have to live with that, I fear. Still, it's cheaper than driving the Mazda which gets 14l/100km. And I fill it once a month.

I feel a bit sorry for you.. I don't really think you are doing anything wrong. I think for some reason there can be a variation car to car.. I am sure Dave (DB08) had a period when his SLX Manual was sitting around or above 6.0 and then came right again by itself

[Doggie 1]

 

[bryanj86]

Yeah... The only time my revs get to 3000 is when I am pulling away fast. Otherwise 2200 or so...

[mjt57]

In our car I can feel the turbo kick in @ around 1800 rpm, so I guess if you're getting to 3k rpm occasionally, the turbo is really working

Not necessarily.

A turbo's demand is based on exhaust gas flow. For example, you can take the engine up to 2,000 rpm or more in neutral and the turbo will be just windmilling, not producing much.

It's when you have wide open throttle which causes a demand for more fuel to match the airflow, that the turbo will be working in earnest.

If I was flooring it in each gear, then yes, the turbo will be working. But I don't unless I need to rapidly accelerate, say, to match freeway speeds when merging. But around town, I use just enough throttle to get it going. And in those conditions the turbo will work according to demand. And as it's a variable geometry one, that operation is made more efficient.

[Phil №❶]

I certainly agree and accept your point that 3k rpm at no load in neutral is very different to 3k uphill with a van towing on the rear. 

[mjt57]

Just an update - Zero'ed the calculator before heading to Melbourne. 240 kays later, back at home and it's reading 5.5l/100 km. Most of it fixed at 110-100 kays, and pussy driving through the towns, though mostly easy going anyway, and 15km suburban roads once off and back on the freeway.

[Phil №❶]

That's what I got overall to Horsham - Mt Barker, so yours will still improve I think. See you can do it. 

[Dazzler]

Just an update - Zero'ed the calculator before heading to Melbourne. 240 kays later, back at home and it's reading 5.5l/100 km. Most of it fixed at 110-100 kays, and pussy driving through the towns, though mostly easy going anyway, and 15km suburban roads once off and back on the freeway.

 

[mjt57]

I was chatting to a mate tonight. He has a VW Passat which has a 2.0l turbo diesel. He fills up with BP "Ultimate" diesel, which I didn't know existed. He claims that it's better than standard diesel because its cetane value is higher.

He said that it improves fuel economy, but the extra cost sort of balances it out.

I'm wondering if any Hy crdi owners here have used BP Ultimate diesel and if so, what were the results?

He was also saying that Caltex Vortex diesel is similar but not as good.

What sparked this conversation was that a pair of BP stations that are located on the Princes Highway, east of Melbourne (at a place called Longwarry) have since changed branding to Caltex and they don't stock the Vortex diesel, but they used to have the Ultimate when it was BP. It means that he has to drive further to fill up because he's fussy about his fuel, I s'pose.

I'll have to check out the local Caltex to see if it sells this Vortex stuff, and to check the remaining BP servos (at Officer, closer to Melbourne) to see if they have the Ultimate. Who knows, perhaps one day I'll see the magical 4.something l/100km...

[AlanHo]

Here are the manually calculated brim to brim economy figures for my last 10 tanks of fuel

mpg         58.79  56.84  53.84  59.39  51.31  52.00  51.01  51.45  56.53  57.80

L/100km    4.81   4.97    5.25    4.76    5.51    5.43    5.54    5.49    4.99   4.89   


The figures in red are when I filled the tank with BP Ultimate - rather than the regular BP I usually use. There was no significant difference in the mix of town and motorway driving or average speeds on any of the tanks - so I have no explanation for the significantly worse consumption when using the Ultimate fuel.

[ElleB]

Aside from when travelling, we always use BP, always the same station and pump, (we love how it froths up and takes so long to fill to the brim, annoying the others waiting to fill.... )  NOT  !!!

 The BP doesn't offer any premium diesel, but we use it as it is very local and has a high turnover via it being a regular truck fill stop for those going over the Blue Mountains.
 I have tried Vortex during a long trip and saw no significant difference for the extra cost.

Thanks Al for these figures....and the report of late on the new model..... I am contemplating moving our 2009 CW on soon, so that it has some warranty and returning to a manual...$$$$$ willing...

Cheers

 ElleB

[Doggie 1]

Here are the manually calculated brim to brim economy figures for my last 10 tanks of fuel

mpg         58.79  56.84  53.84  59.39  51.31  52.00  51.01  51.45  56.53  57.80

L/100km    4.81   4.97    5.25    4.76    5.51    5.43    5.54    5.49    4.99   4.89   


The figures in red are when I filled the tank with BP Ultimate - rather than the regular BP I usually use. There was no significant difference in the mix of town and motorway driving or average speeds on any of the tanks - so I have no explanation for the significantly worse consumption when using the Ultimate fuel.

Why is life so unpresictable? 
We have BP premium diesel here at my local BP. I remember that when they made the switch from regular diesel to premium, they were unable to offer diesel at all for quite a few months. They said it was taking longer than anticipated to produce the correct formula for the premium. I'd love to know what the difference is, because theoretically our cars should perform better and give better economy, I would have thought.
Unless, of course, the re-formulation was for another reason such as more profit for BP, or lower emissions, etc, with no benefit (or perhaps even a detriment) to the indivual.
I don't know which fuel to go for now. 

[Phil №❶]

For me, I go for fuel which loads quickest, I think Caltex Vortex, it doesn't seem to make much difference to the l/100k figures though. If wifey fills up, it's never brimmed  so can't really tell very often.

[mjt57]

Here are the manually calculated brim to brim economy figures for my last 10 tanks of fuel

[chomp...]

The figures in red are when I filled the tank with BP Ultimate

Thanks for that info, Alan. Looks like the "Ultimate" diesel isn't worth the extra dough that BP apparently charges for it.

But having written that, who knows what the differences are between the diesel that you guys get and what we are served up here in Oz.

[Phil №❶]

And they put seasonal additives in for winter conditions too, that could make some difference 

[rustynutz]

On my road trip I filled with Caltex Vortex on one of my fills and, maybe it was just a coincidence, but I think I got the greatest distance from a tank with that fill.....1169.4 km and the low fuel light was yet to come on..... 

[Lakes]

Well i've owned two i30 CRDi's now & the one i have is 6 speed u2 motor with trip pc, the first one did not have a trip PC. i used to always think first one ran best on Caltex Vortex Diesel, but now i just use BP but can't get Ultimate in NSW i know of?
well first car i did almost 100,000k, this one has 28,000k i can get the trip PC to average high 3's if i want just by the way i drive. if i just drive it . it sits on 5.2 and thats all in Sydney.
the first i30 CRDi 5 speed i filleed it to very top  in Sydney , drove around 35k through Syd traffic then down the NSW coast to Melbourne, i was somewhere on a HWY before i turned off to Emerald & i filled up at a BP filled it to the very top all i could get in was 44L the trip k's read 1,044k's i then Drove to Emerald and stayed 4 days did some driving around including trips to Melb CBD, then back to Syd via the borring HWY up middle got back on same tank. only car i've owned that could do that. the new one gets about same economy.
its how you drive, how much weight car carrys, if you tow a trailer & so on that effects economy

[Phil №❶]

Good one Lakes 

[Doggie 1]

Gee, high 3's would be nice.
I have had 1.9 on my previous i30, but that was after refuelling at the top of Greenmount Hill and taking the reading when I got to the bottom. 
It didn't last long.

[Keith]

I just completed a round trip of 428 miles on £50 petrol.
I still had 70 miles available on my Trip computer.
2 of us in the car with luggage for a 3 day stay.
Roads were 95% Motorway, roads dry, traffic moderate to light.
My overall trip MPG at the end of the journey was 49.9MPG.

OK I drove carefully, stuck at around 50 - 60 MPH & we didnt get too many traffic jam ups.

Still think that is remarkable economy.

Chuffed to bits. 

[Shambles]

My overall trip MPG at the end of the journey was 49.9MPG.

Still think that is remarkable economy.

Nah - that's pretty rubbish for a diesel mate