Fuel Used On A Long Run

[Paradroid]

My normal usage for my IS200 is to fill it once a week with 35 litres of fuel (1/2 tank). This gets me to work five days (7 miles each way), and also a run somewhere on the weekend, to Manchester or somewhere like that. I usually get about 200 miles to my 35 litres, and considering the short trips to work this seems pretty good to me.

A few days ago we went to Edinburgh, so I brimmed the tank. I was hoping to get there and back on this tank (it's 200 miles each way). But no chance! On the way back I pulled over for a break, and the fuel indicator was close to the light coming on, and there was only 330 miles on the clock!

I was pretty disappointed with this, but then the motorways were very quiet in places so I had my toe down. Seems like that low 6th gear does economy no good on long runs unless you do 60-70mph?

[Chris.S]

depends how you drive the car

using snow mode i can get between 460 and 500 miles to a brimmed tank

ive done Stoke on trent to glasgow airport and back again on one tank and that was over 500 miles

http://www.lexusownersclub.co.uk/forum/ind...c=53960&hl=

[aido]

ive done Stoke on trent to glasgow airport and back again on one tank and that was 500 miles

Did that take long at 50mph :P

I notice a big difference on mine between just 70 and 80 - can get 200 miles on half a tank just below 70 and about 160 - 170 at 80!! Coming on boost totally destroys that though :o

I just stick cruise on a lot now locked at 68mph - or thereabouts as that's what it maxes out at.

[Chris.S]

lol cheeky

took 4 hours at between 60 and 70mph

remember the tortoise and the hare story ;)

[aido]

remember the tortoise and the hare story ;)

I was asleep when they read that at school

That's not bad going to honest anyway as it's a long old drive up there.

One thing I've noticed since petrol has come back down is that the average speed on motorways has gone right back up again. Might just be me but when it was costing a fortune I was doing 70 miles a day, and was sitting at 68 on the M1 and there weren't that many people overtaking - and most of the ones that did were diesels!

Now it's come back down again there's no end of people tanking it at over a tonne!

[Chris.S]

remember the tortoise and the hare story ;)

I was asleep when they read that at school

That's not bad going to honest anyway as it's a long old drive up there.

got do it again at the end of Feb, hopefully in another car

[Asi]

went to manchester and back and got 440 miles. the speeds were 70-80 ith snow mode one

thanks

[Paradroid]

Well it sounds like it is possible to get good economy on a run. My average speed was 70-80 on the motorway, but there was such clear sections of open motorway I got my foot down a bit more in places. That's probably what got the economy tumbling!

I'm hoping to go to WIM soon with my car, when I do go I'll have to drive more economically

[Asi]

the lexus is very good at long drives and when comes to city driving then it drinks lol

[glennhughes]

Pressing the loud pedal in mine (80/90 mph) i get 17 to the gallon, at a steady 65 i get 27 ish i am a tortoise lol.

[Rob]

at a steady 80mph i get 420-430 miles before the light comes on it works out at 31 - 32 MPG (11 km per litre)

[DJ Wozza]

I use the Snow button and the cruise control to keep at 60mph, get reasonable 33-35mpg.

Any faster and it drinks like a fish.

[FuntimePhil]

have far down the motorway do you have to go?

im not exactly a speed demon but if i drive down the motorway at 60 id be pulling my hair out!! you must have lorrys overtaking you!!

[VVProtocolVV]

I always thought optium speed for economy is around 60mph (my old honda has a light that lights up when its at optium speed/fuel ratio) and not 70mph (wind force comes into play alot as well), plus the fact the fuel usesage on the lexus dash will let you know the optium fuel/speed to be at. It should be the point where its peaked the speed of say 60ish and your just crusing rather then trying to gather the extra 10mph speed. Don't forget about uphills and less downhills etc. I've never really drove my car on journeys (think the furthest i drove was to WIM lol, which i think was around 130miles one way or something).

[SpokesT]

Can we take it then that snow mode is fine at motorway speeds and won't cause any damage to anything?

Incidentally I fitted a K&N air filter and now get about 10% plus more mpg round town, although I also switch to 'snow' when on urban roads at 30mph limits.

[aido]

Can we take it then that snow mode is fine at motorway speeds and won't cause any damage to anything?

Incidentally I fitted a K&N air filter and now get about 10% plus more mpg round town, although I also switch to 'snow' when on urban roads at 30mph limits.

You'll be fine mate - basically the IS uses an electronic throttle control system - so essentially when you're putting snow mode on it's just making the pedal less responsive - no damage at all will be done, it's nothing to do with snow really :)

[SpokesT]

Can we take it then that snow mode is fine at motorway speeds and won't cause any damage to anything?

Incidentally I fitted a K&N air filter and now get about 10% plus more mpg round town, although I also switch to 'snow' when on urban roads at 30mph limits.

You'll be fine mate - basically the IS uses an electronic throttle control system - so essentially when you're putting snow mode on it's just making the pedal less responsive - no damage at all will be done, it's nothing to do with snow really :)

Ta for that. I notice a slight negative jolt when I press the snow buton so I figured it was simply decreasing the power output to the diff. A lad at work is an ex REME mechanic and he suggested that reducing power to the diff which is designed to receive a certain bhp at speed may cause damage long term. But if everyone is doing it without a hitch I'll give it a go on my next long run.

[aido]

Ta for that. I notice a slight negative jolt when I press the snow buton so I figured it was simply decreasing the power output to the diff. A lad at work is an ex REME mechanic and he suggested that reducing power to the diff which is designed to receive a certain bhp at speed may cause damage long term. But if everyone is doing it without a hitch I'll give it a go on my next long run.

One of the more mechanically minded folk should be able to answer that for you mate, have to admit I didn't think it was advanced enough to change output to the diff. Another thing is that it doesn't respond quickly if you say plant it - normally in the auto it would kick down whereas in ETC Snow mode it just slowly brings the revs up.

Maybe you just felt the jolt if you say had your foot at 50% and then the Snow mode reduced that to maybe 25% throttle for the same position?

[Steviewevie]

Yeah it's as Aido suggests, it's suddenly changing the amount of throttle applied even though your foot is in the same position, that's the slight jolt you're feeling, nothing to do with the diff.

[SpokesT]

Yeah it's as Aido suggests, it's suddenly changing the amount of throttle applied even though your foot is in the same position, that's the slight jolt you're feeling, nothing to do with the diff.

I can understand what you are saying, as I believe the throttle is a fly by wire effort, ie not a straight thru cable from pedal to engine?

But how would the mpg shoot up by the 10mpg or so that it does? Is that just an indicator that by depressing the snow button I am effectively lifting my foot off the throttle?

[aido]

But how would the mpg shoot up by the 10mpg or so that it does? Is that just an indicator that by depressing the snow button I am effectively lifting my foot off the throttle?

You got it in one :)

[SpokesT]

But how would the mpg shoot up by the 10mpg or so that it does? Is that just an indicator that by depressing the snow button I am effectively lifting my foot off the throttle?

You got it in one :)

But (I'm enjoying this, it's like my kids when they just kept saying 'why' when they were little!) if I lifted my right foot, the speed of the car would decrease commensurate with the decrease in fuel being delivered. Yet when I hit the snow button, and the mpg apparently increases, the speed remains the same....

[Steviewevie]

But (I'm enjoying this, it's like my kids when they just kept saying 'why' when they were little!) if I lifted my right foot, the speed of the car would decrease commensurate with the decrease in fuel being delivered. Yet when I hit the snow button, and the mpg apparently increases, the speed remains the same....

Snow mode will decrease the amount of throttle applied for a given pedal position. If you're going along on the flat or a slight incline and you engage snow mode, you will probably slow down. There should be a noticeable decrease in power. Does your "Snow" light come on in the dash ?

[aido]

But (I'm enjoying this, it's like my kids when they just kept saying 'why' when they were little!) if I lifted my right foot, the speed of the car would decrease commensurate with the decrease in fuel being delivered. Yet when I hit the snow button, and the mpg apparently increases, the speed remains the same....

When you press the snow button it activates one of those resistors from eBay which gives you the extra MPG

In all fairness mate I have absolutely no clue - unless the MPG dial is linked into the throttle voltage and ignores ETC settings other than default? Probably one for Mat or Colin to be honest!

I never used to take much notice of that MPG gauge apart from to keep it as close to 0 as possible

[Steve_D]

Thought i'd post about my mileage experience in my IS200, travelled from Aberdeen to Gairloch (North west coast Scotland), lots of hills and poor roads so I wasnt light on the gas pedal! filled the car up on Monday night with Shell Optimax, drove there & back on Tuesday, result: 345 miles covered & upon returning home the fuel indicator showing just above 1/4 tank left :) I was more than happy with that, the Scan Gauge said i had 28 litres fuel left in the tank, it normally seems to be wihin a few litres of accuracy at the refill stage. :o

Normally I see 8 miles per litre readings.