Average Mpg

[alien1974]

I find a get a more accurate average mpg figure if i wait for the car to warm up, then zero the trip and drive as normal, if i just let it calculate from start up i get about 15 mpg average, does anyone else follow this or do i have an issue with my 400

[steveledzep]

That's cheating ! I average 29mpg in my IS250. If I were to calculate only when the engine was warm and in 6th gear, I'd be getting closer to 40mpg !

That's what "average" is, mpg calculated over all operating times. Your way makes you feel better, but it is inaccurate.

[Maduggo]

Fill the tank, reset trip meter, run until light comes on, then refil tank and note how many litres it takes, then some basic maths to work out mpg will give you an average based on cold running, slow and fast roads and warmed up running, which as steveledzep says is an average.

Think i got about 20-25 on my old ls400 mk3

[cruisermark]

i dont check any more - i trust the car wont drink more than it needs to lol

[Cotswold Pete]

15mpg sounds about right if you do nothing but city driving.

24-27mpg if you do rural driving (at this time of year nearer 23-25 mpg because of defrost time)

30-31mpg on the motorway over 200 miles at 78mph (4 passengers + boot full)

If you do about 50-55 mph on long run I have found you can get as much as 36-37mpg

All these include any idle time first thing in the morning.

It is never a good idea to fire up the engine from cold and then just belt off down the road, you want to warm the cylinders a little before heading off.

[jpjsavage]

Agree with those figures. That's what mine gives me on my regular runs up to Manchester.

[GEN]

Cotswold Pete says that ".... It's never a good idea to just start the engine from cold and belt.,.." I agree with this in the sense that I would not exceed 3000rpm until the engine has reached operating temperature. On the other hand I have often read that warming up the engine while stationary is not good for the engine and of course takes longer. What is the sense of the forum on this question?

[GEN]

Cotswold Pete says that ".... It's never a good idea to just start the engine from cold and belt.,.." I agree with this in the sense that I would not exceed 3000rpm until the engine has reached operating temperature. On the other hand I have often read that warming up the engine while stationary is not good for the engine and of course takes longer. What is the sense of the forum on this question?

[cruisermark]

well i dont wait for it to warm up - i just drive off but generally my revs are under 2k anyway

[Cotswold Pete]

how accurate are the computers on a lexus?? - my hilux is way out for mpg, it shows 35mpg but in reality I get 25 - 29!

On a long run to Scotland two years ago, I found that the Lexus was pretty much spot on, and in past with Vaux Omega found it to be spot on, so not sure why your Hilux is way out.

As to the below 2k rev, agree, my problem is within 400 yards, I have a 600 foot climb on 1 in 15 to 1 in 10 gradient so like to give the car an extra 30 seconds to warm up.

I have some reports somewhere (probably on an old computer in the loft) on stiction issues at cold start done by Sheffield Uni, but they related to diesel which talked about the issue of head to bore contact etc, etc.

I am not sure if petrol suffers the same issues but my head tells me that a bit more extra time warming up is no harm, and in reality makes no real difference to overall cost of running the 400.

However one observation I have made on this steep climb is that if I defrost the car (engine nice and warm) on a cold day I get a mpg reading of 7.5 mpg, but if I go straight from cold it reads 6.5 to 7 mpg (now that could be because on an icy day I tend to take the incline a little less robustly!!!)

[steveledzep]

I've always believed that it is not good for an engine to warm up just ticking over on the driveway.

Moving off soon after starting enables the engine to warm up under load, it happens more quickly too !

I agree with other posts here, gently does it until operating temperature has been reached.

[oldhazey]

My mk3 is my daily drive,its a 16 mile round trip 5 days a week,weekends are varied conditions and miles.

I average 23 mpg as i work it out from full to empty,it was worse when the EGR pipe was leaking 19 MPG !!

Im alot happier now,considering its a 4.0 V8,another chap at work runs a jag 4.0 sov and cant touch the lex on such good mpg.

[MNP]

I agree with most of the posts here and drive off gently but never exceed 2000 rpm until the temperature guage has settled into it's normal position. I understand that even then the block won't have warmed through so take it gently...

In the old days with mechanical linkages my Dad used to put the heater on cold until the engine had warmed up as he used to say there was no point anyway if the coolant was still cold. This practice I continue with my Land Cruiser, always turn the heater to cold just as I get home. Don't know if she warms up quicker as a result next cold start but of course with the Lexus I can't really do that.

I tend to drive the LS twice a week to Shrewsury and back, that's just over 10 miles each way and get around 25 to 27 mpg. I don't cane her very often!!!

Mark.

[Malc]

Mine gets used every day for all sorts of driving, short, long and tbh I don't worry any more about mpg ........... just fill it up when it hits the orange and a bit ( there's 100 miles left in mine when it hits orange ) and pay the card bill every month and thank heavens I can ........ when one gets older the finer things in life matter more, and to me driving my Ls400 is of prime importance and absolutely one of the finer things in life.

Holidaying with my Ls is also a great thing to be able to do and something I so, so enjoy.

Good food, home comforts, Ls400 driving and that other thing that seems to develop more when one's a tad younger ........ hahahaha .... get my first state OAPension this month ........... OMG ........ now I can afford more miles in Lexii ... ah the bliss of older age eh !!! ........ and getting old quite disgracefully is good too.

Malc

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[Cotswold Pete]

Mine gets used every day for all sorts of driving, short, long and tbh I don't worry any more about mpg ........... just fill it up when it hits the orange and a bit ( there's 100 miles left in mine when it hits orange ) and pay the card bill every month and thank heavens I can ........ when one gets older the finer things in life matter more, and to me driving my Ls400 is of prime importance and absolutely one of the finer things in life.

Holidaying with my Ls is also a great thing to be able to do and something I so, so enjoy.

Good food, home comforts, Ls400 driving and that other thing that seems to develop more when one's a tad younger ........ hahahaha .... get my first state OAPension this month ........... OMG ........ now I can afford more miles in Lexii ... ah the bliss of older age eh !!! ........ and getting old quite disgracefully is good too.

Malc

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Could not agree more (though pension is a little way off, yet).

There does come a time when collecting stuff means you cannot fit it into the house, so why not spend a little more on petrol to travel in luxury.

But all in all the LS400 is by far and away the cheapest car I have ever run, regardless of engine size etc.

I spent 6K on a Vaux cavalier in 1994, and 6K on a Vaux Omega in 2000, and £2.2K on my current 400 in 2012. I never expected the Vauxhalls to last that long, whereas I can see the LS is going to go until it is 25 years old, so long as looked after well.

Am trying to persuade the good lady to do a driving tour of UK this year, but taking a while to convince her, but surely there is no other way to see this green and pleasant land then behind the wheel of a luxury sedan made by Lexus

[Malc]

,,,,,,,,,,, quite agree, the good lady and I, in September 2012 took 15 days up from Kent touring Scotland in Lexii and we travelled, wonderfully, 2800 miles door to door ..... was a glorious experience ( and of course trouble free ) .... unplanned B & Bs all the way for the most part, there was always somewhere to stay that was quite good, and affordable too.

Malc

[harrylime]

On this issue, I choose to remain in total denial, and total ignorance. I prefer to enjoy all the positives of driving this terrific car and do not want these to be offset by my sensible head telling me to get rid, as it's too thirsty

[Malc]

petrol costs are a mere trifle in the running costs of almost all other cars .... with the Ls400 the petrol cost is just about the only challenging cost anyway .................... I doubt my g/fs Mazda 323f ( 1994 ) costs me any less to keep on the road servicing etc wise and certainly petrol wise it's getting maybe 30% better fuel consumption overall ..... I know what I def prefer to have.............. but the g/f wants what she wants and that's an end to any argument I may have about getting her a replacement with a Ls400...... and I sure have tried

Malc

[mikeyv]

LS400 has little or no depreciation, set that against your fuel cost and you're laughing all the way to the bank.

If you're doing a lot of miles, spend £1200 on a lpg conversion, and you'll be filling up at 50 p per litre, doing the equivalent of 40mpg + on petrol.

As daft as it seems, because of the build quality/reliability of these cars, they are ridiculously cheap to run, and a lovely place to be when negotiating our creaking road network.

[Bluesman]

LS400 has little or no depreciation, set that against your fuel cost and you're laughing all the way to the bank.

If you're doing a lot of miles, spend £1200 on a lpg conversion, and you'll be filling up at 50 p per litre, doing the equivalent of 40mpg + on petrol.

As daft as it seems, because of the build quality/reliability of these cars, they are ridiculously cheap to run, and a lovely place to be when negotiating our creaking road network.

LPG at our local fillup is 55p plus less an extra 9p off on an accumulator promotion, next time we get an extra 10p off and then it back to 1p and so on. Laugh? I am in stitches every time I pay. Mike

[Gbneil]

I used to get 20 mpg round town, 24-26mpg mixed half and half and 34mpg on long runs including a wee bit of fun....mk3 ls400 MUCH lamented... So much so I contacted the buyer through eBay today to offer to buy it back of it wasn't working out for him....you don't know what you got till its gone...

[Colin M]

Fully in agreement with the previous few responses.

Absence of depreciation + reliability/build quality far outweigh any extra fuel costs.

I regard these as cheap cars to run and great value for money.

By 4 litre V8 standards, I do not think that they are heavy on fuel. My mpg is probably around 20 in town, 30 on a long run and 25 with a mixture if the two. I am perfectly happy with that.

Having one car with a lpg conversion (paid for by the previous owner) is a bonus and my local lpg fillup is the same price as Bluesman, with a similar reduction of 1-10p on the next 10 fillups.

[Malc]

I used to get 20 mpg round town, 24-26mpg mixed half and half and 34mpg on long runs including a wee bit of fun....mk3 ls400 MUCH lamented... So much so I contacted the buyer through ebay today to offer to buy it back of it wasn't working out for him....you don't know what you got till its gone...

sadly................ but you were warned you would feel like this ........... but your reasons to part company were impeccable .... just very sad

Malc

[Gbneil]

...it's not so much I want another one....I want THAT one back, less that 70k, lustrous paint, no rot....my next lexus I feel will be an sc430 once finances allow

[alien1974]

I used to get 20 mpg round town, 24-26mpg mixed half and half and 34mpg on long runs including a wee bit of fun....mk3 ls400 MUCH lamented... So much so I contacted the buyer through ebay today to offer to buy it back of it wasn't working out for him....you don't know what you got till its gone...

i would love those figures lol, what tyre pressures where you running, so far i have cleaned the tb and the maf, will take it for a run as i haven't driven it since doing the maf.