Fuel consumption IS300H

Digifant · February 20, 2021

Hi everyone,

What's yours IS300H fuel consumption?

I have my IS for about a year. now it has 30k miles on the clock. and I'm worried about the fuel consumption. manufacturer's data says it should be about 60-64mpg, but in fact it's not even close.

NemesisUK · February 20, 2021

See what others have here

https://www.fuelly.com/car/lexus/is300h

ColinBarber · February 20, 2021

With the new WLTP rating system the manufacture's figure is 44.8 to 48.7 mpg, depending on grade and options.

For a non F-Sport, 50 mpg during non-winter months should be possible.

Digifant · February 20, 2021

That's the most disappointing today(

I have Premier model. My consumption is 6.5l/km or 43 mpg(if I converted it right).

Nick W858 · February 20, 2021

I get easy 45-50 in summer - late 50s if I’m really careful. Winter drops to 40-45 with decent runs - current tank 28 based on working from home, lots of short runs plus starting up for an hour a week to keep Battery maintained. Expecting 60-64 is massively over optimistic as most of the manufacturers figures are impossible to attain. For the size of car, performance etc, I think the fuel consumption is brilliant, that said, my last cars were LS400, two ISFs and I also own a 911 that averages c17 mpg so I’m not unhappy. When doing lots of work mileage I can claim pence per mile for 2.0 + petrol and when doing lots of miles prior to the pandemic I was profiting by quite a significant amount in terms of expenses. Also my wife’s RX funnily enough has never even got close to what Lexus claim it will do - 44mpg IIRC. The manufactures cannot be blamed for trying to maximise the numbers - they all do it or did it prior to the WLTP changes - to be honest I never have taken any notice of any of it - common sense with size of car/engine/fuel etc usually is enough to have a good guestimate of what you are likely to achieve.

paulrnx · February 21, 2021

There are more than enough existing threads on here about fuel consumption without starting a new one surely? #boring

Bounce75 · February 21, 2021

I have owned my Is300h Comfort pack/Protection pack for 2 weeks now & have just refuelled it after doing just over 530 miles, it has averaged 47.8 mpg.

I have not been rushing around though as I have been getting used to the car & running it in.

I have made 2 long journeys of roughly 300 miles & the rest have been shorter runs of 10 miles or so.

cidersteve · February 21, 2021

4 hours ago, paulrnx said:

There are more than enough existing threads on here about fuel consumption without starting a new one surely? #boring

why come on here then

Linas.P · February 21, 2021

Other question - what sorts of driving are you doing? If you ever go over 70MPH then MPG is quite poor (or rather in line of this being petrol car with heavy Battery in the boot).

Is this your first car? Because I never had car where manufacturers claimed fuel consumption would translate into real consumption. That said your consumption seems to be fine in comparison with other IS300h...

Expecting 4.4l/100km from heavy luxury car isn't very realistic, but in other hand I agree that manufacturers should provide more realistic estimates. It seems WLTP addressed that.

paulrnx · February 21, 2021

5 hours ago, cidersteve said:

why come on here then

More aimed at the OP. The OP’s first post ever is to start another economy thread. We’ll have to wait and see if the OP is going to engage in this thread or disappear after two posts. It just feels like another economy windup to me.

rayaans · February 21, 2021

Fuel economy is excellent in my opinion. I did a 40 mile trip recently with cruise control set at 77mph and I achieved 45mpg.

Linas.P · February 21, 2021

1 hour ago, rayaans said:

Fuel economy is excellent in my opinion. I did a 40 mile trip recently with cruise control set at 77mph and I achieved 45mpg.

I agree that is good economy, but I agree as well that Lexus claimed figures of 64MPG are not realistic. Besides on empty road just cruising at 77MPH is achievable on say IS250 - so again depends how you look at it.

Alan64 · February 21, 2021

On my 2013 around town im running around 7-100km which i think is ok

rayaans · February 22, 2021

18 hours ago, Linas.P said:

I agree that is good economy, but I agree as well that Lexus claimed figures of 64MPG are not realistic. Besides on empty road just cruising at 77MPH is achievable on say IS250 - so again depends how you look at it.

I suppose that's with all vehicles before the new fuel economy tests.

I think they rated my RX as 45mpg!

Having said that the figured are unusually bang on for my Jag XE-S

Linas.P · February 22, 2021

7 minutes ago, rayaans said:

I suppose that's with all vehicles before the new fuel economy tests.

Now when we have WLTP - absolutely, I think this is legacy issue. Although, Lexus scores no points here by just going with crowd of other manufacturers and using the methodology which they knew wasn't correct or reflective of realistic consumption.

I personally had no issues with previous figures as I took them merely as comparative figure, meaning that car with 60MPG is 20% more efficient than car with 48MPG, even is neither achieve the figures. If that explained to buyer at the point of purchase, probably it is fine, but as well it is known that marketing could have abused it.

royoftherovers · February 22, 2021

25% Professor ? (subject to audit)

Linas.P · February 22, 2021

If you base it off 48MPG as being 100%, then yes 60MPG will be 125% or 25% more efficient,

but if you base it on 60MPG as being 100% then 48MPG will be 80%, or 20% less efficient

I am happy with either case! but you can choose which one is closer to your hart 🙂

paulrnx · February 22, 2021

Even when Linas is wrong he’s right 😉😀

Linas.P · February 22, 2021

I would explain, but do you really care to know?

Digifant · February 22, 2021

On 2/21/2021 at 8:51 PM, paulrnx said:

More aimed at the OP. The OP’s first post ever is to start another economy thread. We’ll have to wait and see if the OP is going to engage in this thread or disappear after two posts. It just feels like another economy windup to me.

Listed 4 pages and didn't found consumption, sorry.

On 2/21/2021 at 4:34 PM, Linas.P said:

Other question - what sorts of driving are you doing? If you ever go over 70MPH then MPG is quite poor (or rather in line of this being petrol car with heavy battery in the boot).

Is this your first car? Because I never had car where manufacturers claimed fuel consumption would translate into real consumption. That said your consumption seems to be fine in comparison with other IS300h...

Expecting 4.4l/100km from heavy luxury car isn't very realistic, but in other hand I agree that manufacturers should provide more realistic estimates. It seems WLTP addressed that.

My daily speed range is 30-50mph. and with one foot on retired driving style. It's my 14th car. The last car with 100% true claimed consumption was Mercedes E220CDI 2007 (with 150000miles on a clock!!!).

First time I believed in Lexus was about 10 years ago. I had GS300 2006, and my best result was +-10l/100km in a city(but without any traffic jams). Quite impressive! So I wanted to try again with IS300H now. And factory claimed consumption was, maybe, in a top 3 reasons to get this model. I assumed that it could be difference, maybe 10%, between claimed and real, 20% - still ok. But not almost half more than claimed!!!!!!!!!!!! I wouldn't buy it if I new it before. I could purchase IS250 which I've been offered with the same colour/mileage/year/range, but £5500 less.

ColinBarber · February 22, 2021

43 mpg is a bit low considering you have had the car for a year and should have adapted your driving to suit a hybrid. But it does depend on your driving style, type of journeys and the weather/temperature. What were you getting during the summer?

The old non WLTP testing just doesn't provide realistic mpg figures for hybrid vehicles. Nothing Toyota can do about that, they were legally obligated to publish those figures if the wanted to sell the vehicle in Europe.

Digifant · February 22, 2021

6 minutes ago, ColinBarber said:

43 mpg is a bit low considering you have had the car for a year and should have adapted your driving to suit a hybrid. But it does depend on your driving style, type of journeys and the weather/temperature. What were you getting during the summer?

The old non WLTP testing just doesn't provide realistic mpg figures for hybrid vehicles. Nothing Toyota can do about that, they were legally obligated to publish those figures if the wanted to sell the vehicle in Europe.

When I collected the car from a dealer, there was 5.1l/100km for couple of thousands trip. I pushed reset strait after collection, and now (year after) it's 6.5l/km. Help me with converting to mpg, maybe I do it wrong. no fast acceleration style

Digifant · February 23, 2021

Look what I found.

LEXUS IS 300H ECONOMY AND EMISSIONS

The Lexus IS 300h has an official urban fuel economy figure of 64.2mpg, and also an extra-urban fuel economy figure of 64.2mpg. You would therefore imagine that the combined fuel economy would be a combination of 64.2mpg and 64.2mpg, in other words…64.2mpg. But no, the official combined fuel economy figure is… 65.7mpg. No we can’t work that out either. However the key thing is that the official emissions are just 99g/km CO2, which translates to a company car Benefit in Kind tax rate of just 11 per cent – which is amazing for a car that drives as well as the IS 300h.

Of course we know that virtually all cars have much worse economy in real-life driving, and hybrids are particularly difficult to achieve their official economy figures in real-life, unless you have a very light right foot. Our average real-life economy over a week with the IS 300h was 45.2mpg. With very careful driving we managed 60.5mpg, so it shows that it can be done, but it’s just extremely difficult to constantly drive so slowly on today’s roads without summoning the wrath of other motorists who aren’t likely to have the luxury of spare time on their side.

Note that in order to achieve 99g/km CO2 – and 65.7mpg – you have to go for SE-spec with 16-inch wheels (as on our test car).

SE is the entry-level spec – which comes with the smaller 16-inch alloy wheels. There’s also Luxury, F Sport and Premier spec. Luxury trim has emissions of 103g/km CO2, and 64.2mpg;...,

Digifant · February 23, 2021

LEXUS IS 300H ECONOMY AND EMISSIONS

The Lexus IS 300h has an official urban fuel economy figure of 64.2mpg, and also an extra-urban fuel economy figure of 64.2mpg. You would therefore imagine that the combined fuel economy would be a combination of 64.2mpg and 64.2mpg, in other words…64.2mpg. But no, the official combined fuel economy figure is… 65.7mpg. No we can’t work that out either. However the key thing is that the official emissions are just 99g/km CO2, which translates to a company car Benefit in Kind tax rate of just 11 per cent – which is amazing for a car that drives as well as the IS 300h.

Of course we know that virtually all cars have much worse economy in real-life driving, and hybrids are particularly difficult to achieve their official economy figures in real-life, unless you have a very light right foot. Our average real-life economy over a week with the IS 300h was 45.2mpg. With very careful driving we managed 60.5mpg, so it shows that it can be done, but it’s just extremely difficult to constantly drive so slowly on today’s roads without summoning the wrath of other motorists who aren’t likely to have the luxury of spare time on their side.

Note that in order to achieve 99g/km CO2 – and 65.7mpg – you have to go for SE-spec with 16-inch wheels (as on our test car).

SE is the entry-level spec – which comes with the smaller 16-inch alloy wheels. There’s also Luxury, F Sport and Premier spec. Luxury trim has emissions of 103g/km CO2, and 64.2mpg; Premier and F Sport have emissions of 109g/km CO2, and 60.1mpg.

Linas.P · February 23, 2021

10 hours ago, Digifant said:

I wouldn't buy it if I new it before. I could purchase IS250 which I've been offered with the same colour/mileage/year/range, but £5500 less.

Yes that is fair point, as well IS250 is just so much nicer to drive, but you won't see more than 28-30MPG in the city thought. On motorway it is about the same.

I would say that ~2010-2015 it was peak of least realistic consumption and then WLTP got introduced, so I think 300h was just on that wave of unrealistic cars.

If that would make you feel better my RC200t does 22MPG... well that is a surprise even fore me, I was not expecting it to be fuel efficient, but I didn't know it was THAT inefficient.