Is300 Mpg!

[SINGH182]

Hi,

only got my 300 last week and so far been a pleasure to drive(around town only).

Today for the first time i used it to drive to work - Coventry to Northampton(around 45 miles each way) all motorway driving,

before i left for work the tank was full with petrol and now im home its just over half empty!, is the mpg on the 300 really this bad? the speed i was doing was no more than 60-70mph(80 when overtaking), before i bought the car the previous owner had just had the service done by lexus (full service).

..been wanting a is300 for ages, but if it continues to drink fuel i might hav to chop it for a 200....dont get me wrong its a 3 litre engine and being a large engine its bound to drink fuel, but i didnt think it would use half a tank.

Will me using fuel like optimax or similar improve mpg?, if so roughly by how much.

Thanks

[maneesh]

sounds like it needs tuning/servicing....that is thirsty

[kam05]

I wouldn't mind upgrading my IS200 to an IS300, but its the fuel consumption that's putting me off....

Are you sure it has been serviced? Check the plugs, air filter, oil etc to confirm.

[SINGH182]

hi,

deffo had a service, jus had a look at the reciept from lexus, cost him best part of £980 from lexus, had everything changed, oil, filter, plugs, belts, tyres brakes etc....i think emissions are fine as it passed mot about 3 months ago.

[maneesh]

fill the tank up first, work out how many litres of fuel have been used for that return journey to work, and then calculate the mpg by hand, which will give us a more accurate idea of how good or bad your fuel consumption is..

cheers

[SINGH182]

may sound stupid, but how do i calculate mpg?

[Unregistered_User]

Try this fella, works a treat :)

The "Can't Be Ar$ed To Do Maths" Way

Jamie

[Rob]

fill it right to the top, reset the trip meter and when the orange low fuel warning comes on check the milage.... you would then have used approx 60 Litres

[Ian M]

fill it right to the top, reset the trip meter and when the orange low fuel warning comes on check the milage.... you would then have used approx 60 Litres

Better still, fill up right to the top and reset the trip meter. Next time you fill up, do it right to the top again – you now know exactly how much fuel you have used and how many miles you’ve covered. mpg = miles x 4.54/litres.

For what it is worth, I also find my 300 quite heavy on fuel – typically about 24/25 which is a mix of town and motorway stuff. Not brilliant, but if I’d wanted an economical car I’d have bought a Fiesta diesel (or similar).

[SINGH182]

thanks for ur replies, ill wait for the tank to get empty and ill re-fill it will optimax or similar

[MrADeveci]

Mate, I'm not being funny .... but you can't buy a 3 litre car ... then worry about the petrol !!

[SINGH182]

jus i had a cayenne 3.2 v6 for a short while and that had a better mpg than the lexus...honest.

[IS300]

Had mine for over 3 years now, drive around 500 miles a week and average 28 to 32 mpg.

And I dont poodle about neither

[MrADeveci]

I would recommend that you clean the MAF sensor.

That could play a big part in the MPG on the car .......... it's located on the air filter pipe .... the black square looking thing, with two screws.

Take it off, and spray some alcohol cleaner into it ... (can't remember exact name)

If that's dirty, and not reading correctly .... it will throw all sorts of weird petrol consumption figures back ! :)

[rhosneigr]

I get about 360mls to a tankfull when pottering around. Throw a trip of about 200mls in I get nearly 400 mls to a tankfull.

[Lexxy_703]

Had mine for over 3 years now, drive around 500 miles a week and average 28 to 32 mpg.

And I dont poodle about neither

Snap! mine is just 4 years old, i don't do the same amount of mileage as you but the MPG is very similar. :)

[Sang]

Had mine for over 3 years now, drive around 500 miles a week and average 28 to 32 mpg.

And I dont poodle about neither

From what i can see the fuel consumption on your IS300 is exactly the same as ours on the IS200, there's another thread here on fuel consumotion and nearly everyone with an Is200 is qote in that 28-32mpg range, i too get around 21mpg...

looking at it at another angle, the 3 liter IS has the same MPG as the 2 liter IS but with more power, surely that's a good thing...

[IS300]

.....er YES !!! :D

[IS300]

Ive got a record of my MPG on every fill-up since owning the car (Have to cos im self employed) and I can honestly say that looking at the consumption it has actually IMPROVED with age.

When the car was new it was averaging in the mid 20's.

When it broke past the 25000 miles barrier the MPG improved and has been around the 28-32 ever since.

I would say this is a good average because all day it's driven on motorways, A-roads, B-roads, stuck on the north circular, stuck in school runs etc.. I use the air con a LOT and even have the engine running with the air con on when parked up having my lunch :P