Posts Tagged ‘ 123d ’

Fuel Economy Run

Today I had to drive from my home in Antwerp, Belgium up to Bennekom in the Netherlands to visit my Citroën which is being repaired there. This is a round trip of 315kms and I thought, just for fun, that I might try an economy run to see what figures I could achieve in the BMW 123d. Those of you that know me or have read my previous posts about driving round the Nürburgring and on German autobahns might think it strange that I would want to drive slowly and economically. But I like a challenge and I’m also a little bit cheap so saving some fuel money is never a bad thing.

My goal was to beat the manufacturer’s claim of 5.2litres/100km (54MPG Imperial/45MPG US). This is a combined cycle claim so beating it on a trip consisting of 95% motorway should be easy but these claims are generally wildly optimistic and recorded under optimal conditions in a lab and therefore I wasn’t sure it would be possible. My average combined fuel consumption before I set off was 7.9litres/100km, a far cry from 5.2litres, and an indication that I had my work cut out for me. However it is worth noting that I drive everywhere at warp 5 with little or no regard for fuel consumption and, as this blog post will show, the most important factor in fuel economy is driving style.

I initially planned to brim my fuel tank with diesel so I could do a more accurate calculation but the service station near my house had a queue and I don’t queue. So instead I just zeroed the trip computer and headed off with less than half a tank of diesel and the trip computer showing a remaining range of just 220kms, a figure based on recent driving history. It looked like I would need to fill up enroute pending a miracle. As it was after 10am traffic on the Antwerp Ring was light and I eased out into the middle lane trying to resist the urge to mash the accelerator into the floor. Initially things weren’t looking good with a figure of around 5.5l/100km showing on the display. However, once I settled down to a comfortable 110kph that figure started to drop slowly but surely until it dropped under 5.0l/100km. Maybe it was going to be possible after all.

The thing about driving super-economically is that it requires a lot of concentration. The thing you absolutely want to avoid is braking as this just wastes your kinetic energy away in the form of heat (in most cars anyway) and this means that you need to plan far ahead, watching for trucks that might pull into your path, watching for slowing traffic up ahead, and trying to avoid having to stop quickly for a red light. It is much better to take your foot off the accelerator and coast in gear if you notice slowing traffic up ahead than it is to brake at the last second. Modern petrol and diesel engines use precisely zero fuel when they are in overrun i.e. when you are coasting in gear and using the engine resistance to decelerate. It is much better to let the engine slow you down than to put your foot on the clutch and use the brakes.

The other enemy of the economical driver is the hill. Fuel consumption when climbing a hill is understandably much higher than driving on the flat. Happily for me, I was driving in the Netherlands which is completely and utterly flat. So flat that the altimeter in my car showed 0 metres above sea level for almost the entire trip. The highest we got was 10 metres above sea level and that was while crossing a huge bridge over a canal. Methinks that real estate purchases in the Netherlands won’t be such a great investment in the event of sea level rises. Although there were no hills on my journey, there were a lot of bridges so I would gradually build up some extra speed before the bridge then allow the speed to decrease slightly as I went up the incline. Trying to maintain a constant speed up an incline will double your fuel consumption. And any speed that you have lost on the way up can be regained on the way down without penalty.

After an hour or so I had worked out that around 110kph was the sweet spot for economy. I could maintain that speed with an instantaneous fuel consumption figure of 3.5l/100km. Going even 10kph faster would push that figure above 4.5l/100km and going slower would start to hold up traffic and that is not practical. My combined figure after an hour was 4.6l/100km and I really wasn’t doing anything special other than driving with a very sensitive foot on the accelerator. I experimented with using the cruise control but found I could get the figures lower myself. Cruise control can’t anticipate traffic conditions or changes in elevation and is a bit of a blunt instrument. I should note that I did make one concession to fuel economy. As it was not a particularly hot day I turned off the A/C and just left the vents open to fresh air. This can make a big difference.

When it comes to economy, the BMW has a few tricks up its sleeve. It has a gear change indicator which shows the optimal point to change up and down and tells you which gear you should be in. It also has an alternator which disconnects from the engine except when you are decelerating so that it never uses fuel to charge the battery. It uses regenerative braking as well to capture some of that kinetic energy which would normally be lost as heat when braking. When you are driving in town it also automatically stops and starts the engine at traffic lights. The standard tyres are low rolling resistance tyres which also aids in fuel economy but I actually replaced mine with regular performance tyres as I didn’t like them so I might have reduced my fuel economy chances there slightly. And instead of using hydraulic power steering which uses a pump running off the engine it has electric power steering which is powered by the battery. All these things, plus the fact that it is an incredibly efficient diesel, add up to a noticeable improvement in fuel economy. Bravo.

I arrived at my destination with the display showing 4.5l/100km and feeling relaxed on account of the fact that I had been taking it easy just cruising along and I didn’t need to be constantly on the lookout for speed cameras. Maybe I don’t always need to drive like my hair’s on fire…

4.4l/100km

My trip home was similarly uneventful although traffic was a little heavier resulting in a few annoying stops and the resulting increase in consumption as I accelerate again. However, by the time I arrived back in Antwerp, the trip computer was proudly displaying a combined figure of 4.4litres/100km (64MPG Imperial/53MPG US). This is not bad for a car that has 204 horsepower and 400Nm of torque, can accelerate to 100kph in 7 seconds and will hit 250kph on the nearest available autobahn. In my opinion it could be a lot better too were it not for the fact that it is a relatively heavy car for its size. My biggest hope for the next generation 1 series is that BMW will invest in weight-saving.

I achieved these figures simply by driving conservatively and turning off the A/C. I imagine it would be possible to drastically slash the consumption even more if one employed hardcore hypermiling techniques like slipstreaming trucks but I’m more interested in the practical everyday possibilities.

Nürburgring! No longer a virgin…

Well yesterday was certainly a milestone in my life. My first, long-anticipated ride around the Nürburgring and it was in a Ferrari 355GTS no less. And it wasn’t exactly being driven cautiously… It was one of the most exhilarating rides I’ve ever had and that’s saying something…

The Nürburgring is a motorsport complex that consists of several tracks including a Grand Prix track (GP-Strecke) located in Nürburg, Germany. The most famous track is the Northern Loop (Nordschleife) which is open to the public most days and is a Mecca for petrol heads from all over the world. At 20.81 kms long it is one of the longest racetracks in the world and with 154 corners it is certainly the most complex and challenging. Most of the corners are blind as the track is on the side of a mountain and there are constant crests, dips and even a couple of potential jumps. It’s not called the “Green Hell” for nothing. It’s fantastic.

I’d been twice before as a spectator so I thought I knew what to expect. I’d also spent a fair bit of time on racetracks back in New Zealand so I was feeling quietly confident. I was in for a wake-up call. This track is not at all like the short, flat, sparsely populated tracks I’d driven on in my Subaru. This is an extremely fast, intense track with chicanes, dips, crests, uphill, downhill, blind corners and it is too long to commit to memory without many, many laps experience. Combine this with constant pressure from Porsche 911’s and BMW M3’s coming up behind me at high speed, not to mention the Ring Taxi, and there was a distinct possibility that I would be reduced to a dribbling wreck.

Ferrari 355 GTS

I drove from Belgium to Nürburg in convoy with a few other people in a Porsche 911, a BMW 3er Touring, and the Ferrari 355. Through Germany this was extremely highspeed at around 220kph so I was well warmed up by the time we arrived. My friend has much experience of the ‘Ring so he took me out first in the Ferrari to experience the track and see what I was getting myself into. This was a very fast lap (I don’t believe we were passed by anything) and initially I was mildly terrified. However, I was able to relax after the first couple of kilometres when it became apparent that my chauffeur knew what he was doing. I’m always happy in the hands of a competent driver. The most amazing aspect of this lap was the grip that Ferrari had through the corners. Barely a wriggle or tyre squeal as we barrelled round the bends. Put that down to very large tyres, low centre of gravity and a wide track. Oh, and the fact that it’s a Ferrari!

Once that lap was completed (in less than 10 minutes) we took a little time to wander around and check out the merchandise in the carpark. Gorgeous sunny day and much eye-candy as you can see from the photos. Ferraris, Lamborghinis, Porsches of every flavour, BMW M3’s, Corvettes, and, the highlight of my day, a Mercedes SLS AMG Gullwing! This Swedish-owned masterpiece in red was being driven round the track along with everything else.

My BMW 123d coupé

Ford Focus RS and Mercedes SLS AMG

Chevrolet Corvette

Ferrari 599

Porsche 911 GT3 RS in Gulf livery

Then came time for me to do a lap in my BMW. It is a 123d coupe and was probably just about the cheapest car in the parking lot. Nonetheless it is still too expensive for me to crash so this was going to be a cautious lap. That and I’d optimistically bought myself 4 laps so I wanted to get my money’s worth. Following a seating position check we set off with my friend in the passenger seat to give me instruction – very useful! I very quickly realised that I wasn’t going to be anything approximating fast as I was quickly passed by a procession of much more exotic machinery but that was ok. I just wanted to survive the first lap with the shiny side up. I’ll freely admit I was pretty terrible initially. Braking in corners rather than on the straight, changing gear mid-corner upsetting the weight balance, missing apexes, I did it all. Even managed to lose the back end about quarter of the way through the first lap although it was masterfully caught and corrected (not by me – clever BMW electronics…). However, with gentle but insistent prodding by my co-pilot I started to take the instructions onboard and remember them.

We continued straight through for a second lap which turned out to be a little messy. The track was quite busy and I was feeling a little flustered. But there was promise showing and the occasional well-executed racing line amongst all the dodgy gear changes and muffed braking points. So I exited the track after the second lap for a break and to take stock. The BMW had done well given that it was entirely road-spec and I hadn’t done anything to prepare it for its track debut. The brake pedal went a little soft but the brakes never faded and it was still braking strongly even after two continuous laps. Bear in mind that’s 42 kilometres! The steering in the 1er is electric so there was no hint of the problem which used to plague my old Subaru, namely the power-steering fluid over-heating. The only component that really let it down was the tyres. They over-heated and I could really feel the grip going out of them. This was my fault for not pumping up the pressure – didn’t think of it – next time.

KTM X-Bow

We then had some lunch – tasty burger – after some of the guys had been for hot laps in a KTM X-Bow! One of them was an F16 fighter pilot and even he came back ashen-faced from the sheer brutality of that machine under braking and cornering. I actually didn’t want a ride – figured the Ferrari was enough pant-wetting exhilaration for one day. While we were lunching the track was unfortunately closed due to a serious Porsche v Armco incident. The Porsche left on a truck and the driver left in an ambulance – hope he’s ok. Happily for me though, I was one of the first through the gate when the track reopened which meant I had a relatively clear, traffic-free lap. This enabled me to focus more on what I should be doing without worrying so much about all the shiny objects in my rear-view mirror. I’m happy to report that my 3rd lap was much tidier than the previous 2 and I was able to concentrate on braking before the corners, turning in and holding consistent lines without upsetting the car’s balance. This lap probably wasn’t that fast either as this time I didn’t have a navigator to tell me what was coming up over the blind crests.

I continued straight through for a 4th and final lap and I believe this was probably my best because now I was starting to remember the track so I could anticipate what was coming up and not brake unnecessarily. There was more traffic than the previous lap but this actually gave me the opportunity to pass a few people, albeit very slow people. (Who takes an X5 SUV on a racetrack anyway!?) There are some lovely chicanes at one point on the track where you can just shoot straight through the middle with the car dancing lightly first left and then right. I enjoyed that bit. And there’s the dipper with a big hump on the way down over which one would get serious air if one wasn’t prepared. That would not be recommended as directly after the jump is a rather serious right hander. Hard to brake or turn corners when your wheels aren’t touching the ground!

I could feel as this lap came to an end that my front tyres had seriously had enough. Grip was reducing and there was beading on the left tyre causing some vibration. Good time to end then. The BMW did well and, despite enormous room for improvement, I don’t think I did too badly either. The BMW is built for the task (M-Sport package and all) and I’m not! Just don’t go to the Nürburgring thinking it will be fun to casually drive round it. It’s a serious racetrack filled with serious drivers piloting serious machines and it doesn’t suffer fools.

Following my 4th lap I exited, rendezvoused with the Ferrari and we set off back to Belgium. Needed a small fuel stop on the way before another high speed run up towards Aachen. Two and a half hours later I was safely home in Antwerp with slightly less brake pads, a lot less tyres, and quite a bit more sunburn. And as for fuel consumption, the BMW 123d endured 5 hours of high speed autobahn, 84 kilometres of Nürburgring thrashing, and still achieved 7.6litres/100 kilometres. Nice.

Home safe

BMW 123d coupé – my other mistress

In addition to the much-maligned Citroen DS that is currently undergoing some restoration I also have a BMW 123d M-Sport coupé. I bought this car new about 18 months ago after a huge amount of research and indecision. Being a fairly low volume model I ended up having to wait 6 months from the time I ordered it until it was delivered. A very painful experience!

Delivery!

Based on the BMW 1 series hatch, the coupé is slightly longer overall and offers excellent front seat accommodation and adequate back seat accommodation for anyone under 6ft. Mine is the top-spec diesel with a 2.0 litre twin turbo 4-cylinder producing 150kW (204hp) and 400Nm (295lb/ft). It will accelerate to 100kph in around 7 seconds and has a top speed of 250kph, not bad for a 2 litre diesel! The huge amount of torque means that motorway cruising and passing other vehicles is effortless, even on high-speed German autobahns. And yet it uses a small amount of fuel, admittedly more than the claimed 5.2l/100kms, but certainly under 7l/100kms.

I went a little crazy with the options to the detriment of my bank balance. Here are the highlights:

Sedona Red Metallic | Black Boston Leather | Brushed Aluminium Trim | Tinted Windows | M-Sport Package | 6M | Comfort Access | Heated Seats | Professional Navigation | Park Distance Front & Rear | USB | Bluetooth | Voice Control | Rain & Light Sensors | Xenon Lights

Since I’ve had it I’ve circumnavigated most of Germany, most of Italy and most of France and I’ve been all over Belgium and the Netherlands. Immensely enjoyable car to drive. I look forward to hearing others’ experiences of the 123d.

Side view

Rear 3/4