[TheBunyip]

After a near lifetime driving Petrol engined cars (badly) I found the switch to CR Turbo Diesel got me thinking about how to get the best out of all  that low rev torque and how to adapt my driving style to get better fuel consumption without sacrificing performance..

I have been hunting for some sound advice that stands up to analysis for sometime. OK I can be a bit of a Geek.  

I can just see you lot using the method described here  to come up with some great guidance for i30 CRDi owners who are also novice diesel drivers.......

Have a look at http://autospeed.com/cms/A_109402/article.html

Then tell me what you think.  

I am pretty certain that there are one or two here who could take the gear change measurements described in the article add some additional guidance on using this kind of information to get the best fuel efficiency from their driving style.

[Shambles]

All I can say is, no way would I rev to 4000rpm before changing gear. Nope.

[Dazzler]

Hi Bunyip... an interesting article...

I've done a lot of experimenting with different gear change points and aside from letting the little diesel idle away from the lights in 1st and 2nd (as some of the guys suggest) I seem to get my best performance/economy compromise by changing gears between 2000 & 2500rpm in each gear... It just seems right somehow...

Everyone on this forum seems to have a slightly different opinion on this one but few seem to rev past 3000 in the diesel unless they are having a "fang"....

Cheers,

Dazz

[TheBunyip]

One thing comes across very clearly in the article.... In carrying out the tests you would NOT exceed the RED LINE value for engine revs. So Shambles may well be correct when he says he would not exceed 4000 revs. As you well know I do not have an i30 (yet) and so cannot comment on the range through which the i30 CRDi operates. The example used in the article is an Old Diesel in comparison with the i30 and appears from the Dyno graph to idle at about 2000 revs or even higher and then ranges up to red line at about 4500 revs. To my novice eye that seems higher than I would expect for a modern Common Rail Turbo Diesel. If d_d  has found something of a sweet spot for gear changing to lie between 2000 and 2500 revs I would guess that idle will be somewhat lower and would not be surprised to see the red line nearer to 3000 than 4500 revs.

I am sure that people like Lakes and Thumper and several others who post here would be better placed than I to talk about maximum revs for the i30.

My interest is in seeing a simple but practical objective method to determine ideal gear change points. (Ideal = safe, economic, efficient and effective i.e. best performance) As I think the article shows those points will be well below the red line values because of the shape of the torque curve.

As you may also have read Hyundai (and possibly other manufacturers) will be introducing a dashboard display in the next generation of cars to provide a prompt indicating when to change up or down. It seems that the "Average Motorist" will benefit greatly from improved fuel consumption and because engines will operate at nearer to peak efficiency for more of the time emissions will also improve considerably in practice. I would just like to be able to come close now. Although 3L/100Km as discussed elsewhere seems beyond me.

As you probably know real world emissions are currently much worse for any of the cars tested by various agencies than manufacturers can achieve in the standard test cycles.  Helping drivers to change up or down at ideal points is no longer about skill but about fuel efficiency and environmental concerns. One of the senior designers at Peugeot has indicated that a fully computer controlled Automatic Transmission may become compulsory if EURO6/7 emission standards are to be met in practice as well as in the test cycles. If that happens lots of motorists and Old Farts like me will bemoan the loss of our preferred manual boxes. Whilst Automatics seem to be the popular choice in countries such as the USA and Australia, Europe has yet to fall out of love with taking personal control of the transmission.

[foxey]

I drive my diesel SLX to 3000+ all the time.. especially in 1st & 2nd almost always to 4000 - 4500 when I get the chance, after all the redline is about 4800 so there should be no problem doing this ... I like to use the power and torque of the engine, and is the reason why I chose the diesel over the petrol - driving pleasure.. (as well as the fuel economy..)  having owned 56 cars in my lifetime (all petrol) this is the first diesel and I don't think I can go back.. in the 3000km I've done in the short time I've owned this car (about three weeks) I am averaging 5.8lt/100 in town driving, so I enjoy the drive and the economy is better than the 13-14lt/100 I was getting out of my previous vehicle.. I agree that not giving it full revs is better for economy.. the best I've done with mine taking it easy like this is 3.9l/100..
In anycase, the power drops off so markedly at close to redline that you can't really overdo it.. in my experience if you drive within the torque band then that is when you get the most out of your car.
Maybe I am driving it incorrectly - after 56 petrol cars I guess I could be still hanging on to that legacy....

[EymaTeapot]

Hi Foxey,

You make an excellent point, Its not all about fuel economy. Yes Fuel economy was high on my list of priorities when i choose the i30 but performance was just as high.
Maybe because we own one of the most fuel efficient cars on the market, we get carried away trying to get the absolute best fuel economy. You have proven a good point though, You can drive this wonderful little car hard, have some fun and still get exceptional fuel economy. 5.8lp/100 is still good no matter how you look at it.

Cheers

[foxey]

Thanks Eyma.. I piled on 35,000k in my previous car in the last six months so by that reckoning I'm doing about 70,000km per year, and that's been the case for the past 10 years or more, so I decided to go diesel in order to save fuel - but I didn't want to sacrifice performance, you are so right - even 6lt/100 is great and is saving me about 7lt/100 from my previous car - work that out at 70,000km x 7 ltrs / 100 = 4900 litres per year saving.. ouch..  so driving it a little hard doesn't worry me..

[Dazzler]

Hi Foxey,

Sounds like you'll get value out of your warranty 350,000 kms! 8-)  

Cheers,

Dazz

[foxey]

Hi Dazz,

I am working between IT Support and the Food/Beverage Industry.. keeps me on the road all day everyday..

[Dazzler]

An interesting mix...

With your driving style and your huge mileage you could prove to be a wealth of information going forward...

Rgds,

Dazz

[foxey]

well, to give you an idea, the last few cars I've had and mileage are as follows:

Jan 2001 to Jun2002 - Subaru Forester GT Turbo - 135,000km
Jun 2002 to Jun 2004 - Lexus IS200 - 155,000km
Jun 2004 to Nov 2007 - Commodore Berlina - 170,000km
Nov 2007 to Jun 2008 - Suzuki Grand Vitara - 45,000km
Jun 2008 to ? - Hyundai SLX Diesel ...

I'm too frightened to list them all......

[eye30]

All this about what rpm to change I just let the car drive it self.

It tells me when it wants to change and I'm averaging 53 Mile to the gallon, mainly town driving.

[Dazzler]

Hi Foxey...

Interesting list of vehicles and amazing mileage figures (it's a wonder you don't get "bed sores")

Eye,

That's what I was getting at in an earlier post... you just kind of "know" when to change....

Rgds,

Dazz

[TheBunyip]

At last I have managed to find a slightly edited Dyno Graph for the i30 1.6 CRDi. I found it in a Hyundai web site brochure for the i30. It shows both the standard 1.6 and the low power 1.6 which I think is to be used in the iBlue version (low consumption & low CO2 emissions, reasonable performance from a six speed manual box)

For those who may be a little puzzled with the difference in their experience of driving an i30 and the story of the old Peugeot 405 described in the article a comparison of the two graphs should be interesting. (In my ignorance) I have never seen a Torque graph like this for the i30 start off near max and stay near horizontal for most of the range. Seems to me as if the climb to high torque from idle has been edited out for marketing purposes. I reckon that leaving it in would have made the graph even more impressive.

Perhaps this graph explains why you lot are getting such good consumption when you stay below 3200 RPM. Of course I am sure that there are others who will make more sense of the graph than I can.

I started looking for a Dyno Graph from one of the companies selling Tuning Boxes for this engine. One has claimed to have got 150BHP or about 112kW from this engine in a Kia Cee'd. I'd love to see the Dyno Graphs comparing Before and After for that little modification.

http://www.aouq23.dsl.pipex.com/130-CRDi.pdf

[Dazzler]

Thanks BunYip,

In Britain (unlike Australia) they apparently get the choice of 66Kw or 85kw diesel models (as per the graph) The lesser one is taxed at a lower rate I believe.

I like my 85kw/ 255nm model...  

Cheers,

Dazz

[Thumper]

When I do my economical driving, I do not go over 2,000rpm. (Unless I am in 5th gear and on the highway)

My last tank, 600km at 3/4 tank, 800km for 1/2 tank. 1050km at 1/4 tank. (Still waiting for the low fuel light to come on)

[Dazzler]

Hi Thumper.. like your avatar.. simple (but cute and effective)!

[TheBunyip]

The iBlue version with the low power 1.6 should attract a considerably lower rate of tax when it eventually appears in the UK. There is no  mention of a 66kW CRDi on http://www.hyundai.co.uk just yet. If it were available just now I suspect the UK would see some heavy marketing to push it as a City Car of choice. UK Diesel nudging AU$3.00/L will provide some additional incentive for a model with 15% better consumption than the current frugal i30 CRDi. With a 5star Euro NCAP rating they might even sell a few to replace Chelsea Tractors for the School Run. Methinks we might agree.

I suspect that the UK and others who want the ultra green i30 will have to wait for the new Hyundai European factory in Nošovice, Czech Republic to come on stream next year. They are planning to start a second shift in March 2009 so it looks as if they anticipate the demand for the i30 to continue to grow. The i30 is selling far too well everywhere that I see it mentioned for those of us who would like to avoid paying top price. That auguries well for holding resale values though.

[Dazzler]

Sorry Bunyip my mistake...

Looks like they do sell it (the 66kw diesel) in other parts of Europe and possibly Ireland too... but not in Britain as such (I must have misunderstood something said on H-F)

Cheers,

Dazz

[eye30]

....... when it eventually appears in the UK. There is no  mention of a 66kW CRDi on http://www.hyundai.co.uk just yet.

When I was in my dealers 3 weeks ago they mentioned this as "here" but when I asked to see one they didn't have one but expecting soon!!

I'm back next week to hopefully pick up my 2nd remote so I'll ask again.