Is220d Fuel Economy Fixes?

[Gareth]

Mine's up to 170 miles now, and I'm still on 28.5mpg.

The ecu remap was done before I got it.

I'm hoping to see it creap up into the 40s when I get to the 1k mark

[Scarlet Pimpernell]

Maybe the ECU remap has remapped the Tank Ave to always show 28.5

It does feel different to drive though, somehow "lighter"

the wife always struggles to drive it. All of the controls are too heavy for her - the clutch, Handbrake, even the accelerator - which you need to stand on at times - especially when getting out of a busy junction. Mind you she's only 4ft 11 (sorry - 5ft 3 avec stilletto)

Since the mod, the throttle response has improved. I can see how that could give poor consumption as you now have a will to want to drive quicker!!

[Gareth]

Serves you right for marrying tinkerbell.

[The Mole]

The main reason for poor mpg is driving style. It will not suddenly improve by 40% as you do more mileage.

We have had several customers complain about poor mpg, and several report that they are happy with the 40 - 45 mpg that they are getting.

I personally have driven a couple of customers cars who have complained about poor mpg and instantly got 38 - 43 without trying as I know how to extract the best from them.

The engine is very powerfull and using the torque and power, enjoying the 2k + rpm shove in the back when the turbo really kicks in will yield high comsuption - as will batting up and down the motorway at 85+ mph

I can't give a set of instructions of how to drive a car as that would be nothing short of patronising, but they can and will give decent mpg if driven in a certain manner that doesn't involve driving Miss Daisy, or labouring 6th at 60mph.

It was the same when the RX400h was launched. Some customers came back complaining they could only get 27mpg. You ask the customer to take you out in their car and instantly they are putting their foot down, overtaking all the traffic using heavy on or off throttle inputs. You ask to swap and drive their car back to the centre driving smoothly and in sympathy with the system and technology and hey presto 35mpg. The customer then says "Well, if you're going to drive like that then of course it will do the figures..."

Yup..... Performance OR economy, not both at the same time.

I understand that lots of you might be used to driving VW/Audi 1.9 tdi's with good performance and 50+ mpg, BMW's too, and to suddenly find that you have to struggle to get 40 must be a bit of a shock, but as soon as the competition bring their Euro 5 complient diesels out, it will be the same story for them. Lexus were just the first to market with a Euro 5 diesel. The emissions equipment on the new diesels is extreme to say the least and really does strangle the motor.

[Scarlet Pimpernell]

Serves you right for marrying tinkerbell.

Cheers, I'll tell her that:

Signed: Peter Pan

PS - what I find hard to believe though is that with Euro 5, the engine is cleaner, but uses more fuel. Wow, that's supposed to be good? Rules are ruiles

[Gareth]

The Mole:

Are you saying that consumption will not get better for me once the engine has had some time?

I'm driving it how I would expect to have to to get mpg.

I keep her below 2.5k rpm and I use slow input and patience.

The engine is currently more noisy and labour-some than I hoped it would be once it's had hoped it might be after it's had some time to bed in.

[Harrydavy]

The main reason for poor mpg is driving style. It will not suddenly improve by 40% as you do more mileage.

We have had several customers complain about poor mpg, and several report that they are happy with the 40 - 45 mpg that they are getting.

I personally have driven a couple of customers cars who have complained about poor mpg and instantly got 38 - 43 without trying as I know how to extract the best from them.

The engine is very powerfull and using the torque and power, enjoying the 2k + rpm shove in the back when the turbo really kicks in will yield high comsuption - as will batting up and down the motorway at 85+ mph

I can't give a set of instructions of how to drive a car as that would be nothing short of patronising, but they can and will give decent mpg if driven in a certain manner that doesn't involve driving Miss Daisy, or labouring 6th at 60mph.

It was the same when the RX400h was launched. Some customers came back complaining they could only get 27mpg. You ask the customer to take you out in their car and instantly they are putting their foot down, overtaking all the traffic using heavy on or off throttle inputs. You ask to swap and drive their car back to the centre driving smoothly and in sympathy with the system and technology and hey presto 35mpg. The customer then says "Well, if you're going to drive like that then of course it will do the figures..."

Yup..... Performance OR economy, not both at the same time.

I understand that lots of you might be used to driving VW/Audi 1.9 tdi's with good performance and 50+ mpg, BMW's too, and to suddenly find that you have to struggle to get 40 must be a bit of a shock, but as soon as the competition bring their Euro 5 complient diesels out, it will be the same story for them. Lexus were just the first to market with a Euro 5 diesel. The emissions equipment on the new diesels is extreme to say the least and really does strangle the motor.

Your knowledge & advice is excellent Mr Mole but if I had known all of this a year ago I wouldn't have bought the car. A Euro 4 Beemer would have been a much better option (just fewer Toys)

[rottwailer2001]

The main reason for poor mpg is driving style. It will not suddenly improve by 40% as you do more mileage.

We have had several customers complain about poor mpg, and several report that they are happy with the 40 - 45 mpg that they are getting.

I personally have driven a couple of customers cars who have complained about poor mpg and instantly got 38 - 43 without trying as I know how to extract the best from them.

The engine is very powerfull and using the torque and power, enjoying the 2k + rpm shove in the back when the turbo really kicks in will yield high comsuption - as will batting up and down the motorway at 85+ mph

I can't give a set of instructions of how to drive a car as that would be nothing short of patronising, but they can and will give decent mpg if driven in a certain manner that doesn't involve driving Miss Daisy, or labouring 6th at 60mph.

It was the same when the RX400h was launched. Some customers came back complaining they could only get 27mpg. You ask the customer to take you out in their car and instantly they are putting their foot down, overtaking all the traffic using heavy on or off throttle inputs. You ask to swap and drive their car back to the centre driving smoothly and in sympathy with the system and technology and hey presto 35mpg. The customer then says "Well, if you're going to drive like that then of course it will do the figures..."

Yup..... Performance OR economy, not both at the same time.

I understand that lots of you might be used to driving VW/Audi 1.9 tdi's with good performance and 50+ mpg, BMW's too, and to suddenly find that you have to struggle to get 40 must be a bit of a shock, but as soon as the competition bring their Euro 5 complient diesels out, it will be the same story for them. Lexus were just the first to market with a Euro 5 diesel. The emissions equipment on the new diesels is extreme to say the least and really does strangle the motor.

It is an off-topic, but "The Mole", doy you know anything abut "b pillar" wind-noise at 120km/h? My IS220d has ana annoying wind noise in both "b" pillar near the ears of driver and passenger and it is very annoying. Do you know any solution for this problem?

Thanks in advance

[Gareth]

It is an off-topic, but "The Mole", doy you know anything abut "b pillar" wind-noise at 120km/h? My IS220d has ana annoying wind noise in both "b" pillar near the ears of driver and passenger and it is very annoying. Do you know any solution for this problem?

Thanks in advance

I'd suggest that you start a new topic for that, for several reasons:

Anyone who does know about it would see the topic in RSS, but wouldn't know you were asking about it in here, so can't answer.

Also People in the future will want to know the same thing, but won't find your question and the answers cos it's buried in another topic.

A lot of the time Off-Topic doesn't matter, but for a case like this it kinda does.

You can always prod the mole in pm to look at the topic, if he doesn't notice it.

Hope you don't take offense at that.

G

[romaro]

So for those that have had the mod, is the acceleration now smoother?

I quite like the kick in the back at about 2,000rpm that I currently get. :D I'm also concerned that depending on driving style and typical journeys, having the turbo kick in earlier could potentially mean worse fuel economy.

[rottwailer2001]

It is an off-topic, but "The Mole", doy you know anything abut "b pillar" wind-noise at 120km/h? My IS220d has ana annoying wind noise in both "b" pillar near the ears of driver and passenger and it is very annoying. Do you know any solution for this problem?

Thanks in advance

I'd suggest that you start a new topic for that, for several reasons:

Anyone who does know about it would see the topic in RSS, but wouldn't know you were asking about it in here, so can't answer.

Also People in the future will want to know the same thing, but won't find your question and the answers cos it's buried in another topic.

A lot of the time Off-Topic doesn't matter, but for a case like this it kinda does.

You can always prod the mole in pm to look at the topic, if he doesn't notice it.

Hope you don't take offense at that.

G

Ok, I do it

[The Mole]

I'll look into the B pillar noise. 9 times out of 10 it is a very small gap or misalignment in the window seal trim. Not common, but I have seen it twice before.

With a few thousand miles, yes the engine will run a little more efficiently, but we are only talking 2-3 mpg at best.

Driving at revs where the engine is on boost will make it more efficient as the turbo is helping the engine breath. You will only use more fuel on boost if you are using it to accellerate quickly with a wide open throttle.

The ecu mod doesn't change the boost you get a 2k rpm, but it will allow the engine to be a little more flexible below 2k giving a slightly more unioform torque curve as boost comes on-line due to different injection mapping.

On the emissions front, the IS diesel engine is the cleanest (total emissions) diesel for its size in the world. Has much lower NOX, particulates etc.

Also, if you pay co car tax, euro 4 will get VERY expensive as soon as they tax you against euro 5. People with an IS will be much better off. October next year for those thart care.

[Scarlet Pimpernell]

Thanks Moley - this is exactly my experience since the ECU remap.

The engine pulls much better, and actually feels a tad more like the Sport. It is much smoother and as I said before you don't have to stand on the pedal to get going. The "flat" spot from 1st to 2nd is much less pronounced.

However, fuel consumption hasn't changed too much, still averaging a gentle 42-44mpg. Much more driveable tho'....

PS - I noticed a stepped change in terms of consumption at approx 5000 miles. It seemed be able to give 40's MPG easier...

[Harrydavy]

I'll look into the B pillar noise. 9 times out of 10 it is a very small gap or misalignment in the window seal trim. Not common, but I have seen it twice before.

With a few thousand miles, yes the engine will run a little more efficiently, but we are only talking 2-3 mpg at best.

Driving at revs where the engine is on boost will make it more efficient as the turbo is helping the engine breath. You will only use more fuel on boost if you are using it to accellerate quickly with a wide open throttle.

The ecu mod doesn't change the boost you get a 2k rpm, but it will allow the engine to be a little more flexible below 2k giving a slightly more unioform torque curve as boost comes on-line due to different injection mapping.

On the emissions front, the IS diesel engine is the cleanest (total emissions) diesel for its size in the world. Has much lower NOX, particulates etc.

Also, if you pay co car tax, euro 4 will get VERY expensive as soon as they tax you against euro 5. People with an IS will be much better off. October next year for those thart care.

Hi Mr Mole

Just a few more questions please.

1:Was the ecu mod brought in specifically to allow 6th gear to be used at a lower speed?

2:Also my choke seems to be on for a very long time (41 mins timed last week) not good eh?

3: The complete jet change that other people have had done reg mpg, any comments??

Than q

Harrydavy

[The Mole]

Any mpg figures that start with a 4 are a result.

The 'choke' as you say is not a 'choke' in the old fashioned sense of the word. It is an 'idle load' compensator. If you put a load on the engine at idle from the a/c, heated seats etc, the ecu ramps the idle speed up to about 1100 - 1300. This is to stop unburnt diesel fouling the cat and injectors if the engine revs are dragged below the set idle speed due to load. All in the name of emissions etc.

The ecu mod was brought in to answer some of the critisism that the car has had from launch - 6th, sluggish under 2k rpm, vibration in 6th due to labouring at 70 mph etc. Oh, and a little fuel economy, but that is only a by product of the mod if your driving style complements the new mapping.

The injector change is not a modification, just a change under warranty if there has been a problem. The only injector that is different is the '5th' injector that is there purely to help with emissions and cat cleaning.

I picked up my new (and first) diesel a few days ago with every mod bell and whistle available.

Taking my Lexus cap of for a minute, all I can report is that it is very smooth, very quiet, very well made, but the compromised gear rations are driving me mad. There, I've said it.

Any car you buy will include a compromise of some description. It could be price, dealer service, spec, quality, depreciation, looks, space, practicality - all sorts of things.

There isn't a car on the road that if you bought, you wouldn't be compromising on at least 2 or 3 of the above.

The Lexus delivers on many fronts, and in my case the compromise is a little drivability. It's a frustration I share with you all and one that has been brought upon us due to emission regs.

Notice how nobody complains about the diesel sport......?

This is because it has the gear ratios that the factory wanted to give it, but yields higher co2 emissions making it uncompetitive under the CURRENT euro 4 taxation regs......

[Gareth]

Are you saying that the diesel sport gives better economy?

[Harrydavy]

The injector change is not a modification, just a change under warranty if there has been a problem. The only injector that is different is the '5th' injector that is there purely to help with emissions and cat cleaning.

Several chaps have been on and posted that they have had all of the jets replaced with dramatic results

also

This is my main bugbear, if getting 40mpg is a result then how is the car advertised with such higher figures (big con and illegal)??

Are you saying that the diesel sport gives better economy?

No, i had one for 3 days and averaged 30mpg but Mr Mole is right it drive much better with half the gear changes!!

[tyrrp]

This is my main bugbear, if getting 40mpg is a result then how is the car advertised with such higher figures (big con and illegal)??

You have to remember that the figures are not made up or even tested by Lexus. They are government figures that are reached using a set number and type of tests done on a test rig not on public roads. The car doesn't have to deal with resistance etc and is driven in the perfect way for economy which is not how most people drive.

[FinLex]

I don't think the official tests are driven in the perfect way for economy. They are driven the same way for each car, while each car has it's own way of reaching the best economy. The figures are correct in that they don't come from Lexus, but still not very accurate because the tests are not driven on public roads.

I would say the Sport gets very similar economy to the non-Sport. With the Sport you have more of a choice to pick the best gear for every situation. This compensates the fact that the high-speed driving comes with higher rpms.

[Scarlet Pimpernell]

I always say it's like driving in gears 1-6 on a mountain bike in the Sport, and gears 7-12 in the non-Sport, if you know what I mean. The differential (centre sprocket on the mountain bike) is what makes the difference...and in the same way as a bike, the car seems to run out of steam quicker due to the narrow power delivery, but is probably fleeter on the foot as a result and hence is less economical.

The non-Sport on the other hand feels slightly lethargic, but is able to make slightly better use of the narrow power delivery which it can stay in a tad longer in any gear and hence gives you a better "shove" in the back when accelerating.

It's horses for courses - the Sport is better in town and lower speeds on A roads, the non-Sport better on the Motorway - OTHER THAN when you want to do 70 in 6th. The Non Sport always feels uncomfortable unless you're going down hill at 70 in 6th. The Sport on the other hand revs higher and sits happily at 70 in 6th...

It's a tough one, but overall I reckon the Sport makes a better case for itself in the UK when you're constantly speeding up and stopping...though most of us would struggle to better mid 30's (though some get 40+).

The ECU changes to the non-Sport for me at least are worth it - again - anyone with the Sport had this done yet?

I really don't think we'll ever get above early 40's in normal conditions. I keep comparing the car to my old A4, which even with 47bhp less felt as quick most of the time (with more gear changes), but that was down to better torque spread. So I've stopped comparing them...and like Mole says, I'm now waiting for the latest legislation to kick in, and force BMW and Audi to follow suit. Then it'll be time to go for some test drives

[The Mole]

Sport is not quite as economical, but much nicer to drive due to more appropriate ratios.

Every car has the same government test in a big fridge on a rolling road - it's the only way to get repeatability into the test. If a car doesn't do that in the real world with a real driver, then the test is at fault, not the car.

Just so we are clear - there is not a replacemt injector that will make a difference. The onldifference would be if there was a fault with the original one and it has been replaced with the same design that is working correctly. The only thing it could be is if they have done the ecu mod at the same time, or the engine has been struggling in limp mode for a while.

The only injector that has changed in design is the 5th injector.

[javadude]

The ECU changes to the non-Sport for me at least are worth it - again - anyone with the Sport had this done yet?

I tried but my dealer couldn't find anything about it. I'll try another dealer when I get round to it.

[Harrydavy]

Just so we are clear - there is not a replacemt injector that will make a difference. The onldifference would be if there was a fault with the original one and it has been replaced with the same design that is working correctly. The only thing it could be is if they have done the ecu mod at the same time, or the engine has been struggling in limp mode for a while.

The only injector that has changed in design is the 5th injector.

But lets be clear, thats what I am saying, has there been a lot of cars with faulty jets & various dealers have changed all of them before the warenty company put an end to that???

[The Mole]

Lots of cars were coming in with warning lights on and poor running due to failed 5th injectors. Before Lexus came up with a fix, normal diagnostics pointed to injectors, so dealers changed then as a matter of elimination, even though there wasn't really anything wrong with them - but changing the 5th one and resetting the fault code sorted things out for a while....

[scott]

But lets be clear, thats what I am saying, has there been a lot of cars with faulty jets & various dealers have changed all of them before the warenty company put an end to that???

Yep - had ALL of mine changed and it made a significant difference - mid 30s to low/mid 40s, without changing my driving style. It also improved performance and permitted me to use 6th gear @ 60 mph. It hasn't been back since the injector change so I haven't had the ECU remap. I have noticed fuel economy dropping as it's approaching 20000 miles so I'm assuming it is in need of a service, also roadworks on the A34 haven't helped. At the time I was told that I had the "wrong type/make" of injector fitted (Jan 06 car).