MPG on IS 300h etc.

[Hadrian]

I'm sure this question has been asked before, but I couldn't find it on a search.

I have only recently purchased a 2015 IS 300h with just over 21,000 miles on the clock. I was wondering what sort of fuel consumption I should expect ?

It won't be used for driving around town, shopping etc, mostly for longer runs. I am not a foot to the floor boy racer.   On my previous car (Civic Hybrid)

I would get just over 50mpg on a run, and something like 38 around town. I've seen a figure of 60mpg quoted for the IS, but that sound optimistic.

[NemesisUK]

Not the IS variant but the RC300h, I get 30-35mpg out of town and ave 42mpg in town. 

In the summer the in town mpg goes as high as 47mpg but the cold weather knocks that back to high 30's.

These hybrids are definitely built for urban/town driving, once on the open road it's pretty much 100% petrol driven

[Guest]

Cynical maybe but I suspect also built to get road tax and business tax down and sales up. Environment? Helps with marketing.

Peter's figures are similar to the IS250 V6 out of town but probably twice as good in town.

I can get 38mpg out of a 5ltr on the motorway but of course the govt don't see it that way.

 

[Thackeray]

60 mpg is definitely optimistic. The 16 inch wheels on the SE are supposed to get better mpg than the larger wheels on other models but even they won't get 60 mpg routinely.

An average seems to be around 44 mpg, according to spritmonitor.de fuel consumption site.

In a year's use I did 42.1 mpg, measured from tank fill-up to fill-up. The dashboard display is around 10 pct optimistic and showed an average of 46.2 for each tankful over the year.

The best was 51.1 on a tank that included long motorway trips. The dashboard claimed 55.1.

Over the winter, when I was only doing four-mile, slow town-driving trips in sub-zero temperatures, with the engine started from cold each time, lights on, heater on, heated seats on, wipers on, air conditioning on, I got 30.7 (the dashboard showed 33.5 for that tankful.)

Although it does well around town in general, helped by the energy regeneration, there's a common misunderstanding that you're saving money by using the electric motors only. All the electricity is second-hand energy, as it was originally generated by the petrol engine, either directly when the engine is running, or indirectly when it's being regenerated from braking, (using the kinetic energy that the engine created.)

It's the efficiency of the engine that will give high mpg figures for a 2.5 litre. So cruising on motorways can be quite efficient, as shown by the figures above.

You're fortunate to get the car as the weather warms up - that helps keep the fuel consumption down. But expect the mpg numbers to fall away from around November unless you only do motorway driving.

Hope you enjoy the car!

[rayaans]

On longer runs you should be getting about 40-50mpg. 

[Mr Vlad]

There''s always flannl when mpg is asked about. My similar mileage car has had a worse of 19mpg (1 mile to the local asda) and a one time only 75mpg on a 10 mile circular route a mix od A roads and motorway. 

14 mile commute split even between A road and motorway I get 50mpg every day. On the way home tho in a bit of traffic it' down to 44mpg.

What you'll notice is when on the motorway. I do more than 70 and it's the engine revs that get me every time. Constant speed and the revs areally as low as 1100 to a high of 3000 when going uphill. Rochdale to Leeds I'll always get 50mpg.  That to me is superb.

Enjoy your car 

[ColinBarber]

My fuelly figures are below in my signature, the IS300h was an F Sport which has measurably worse mpg compared to the other models due to the larger wheels and greater aero drag. 

[Carl1983]

Hi

I have an F Sport with the 18 inch wheels. my driving is always long runs with the odd local run every now and then. I've owned it for 12 months now and the lowest tank ever was 48mpg. Average for the year is 50mpg which I'm extremely happy with. winter time I drop onto smaller 16 inch wheels with winter tyres and if anything my mpg improves .

hope this helps 

enjoy the new motor 

[Hadrian]

Thanks for the replies.

 

On a similar subject, this is the first car I've had with paddles on the steering wheel. I'm still not exactly sure what they do.

 

[Tel]

In my 2013 IS F Sport mpg was as follows in Sport-Mode only.

Winter c. 43 on commutes c.12 miles  & 50+  on 100 mile Motorway spurts.

In Summer c.10% higher figures.

On Continental journeys to France & Italy in Summer I averaged c. 58 & when I drove up the Jura mountains with 4 on board I averaged 25 & saw 60+ returning to the valley floor.

My new Motor is a touch better as the Battery kicks in below 8 mph

Am driving to Lake Garda later this year & will be interested in the figures which in France on their Autoroute I got c.58 doing 80 mph But c. 38 in ITaly with average speeds of 90 mph when traffic allows 

3 figure speeds result in the figures below 30 

Tel

[ColinBarber]

8 hours ago, Hadrian said:

Thanks for the replies.

 

On a similar subject, this is the first car I've had with paddles on the steering wheel. I'm still not exactly sure what they do.

 

Really it is just a gimmick on the hybrid transmission, but if you put it in manual you can pretend to change gears using the paddles.

The main use is if you know you want to overtake you can 'drop down a gear' to bring up the engine revs beforehand so you don't have an acceleration delay when press down the throttle - you can do this in Drive, you don't need to be in manual mode.

[tanimbar]

Have IS300H, 2014, SE, owned two years and never reset trip computer; shows 51 mpg. Seems the average annual consumption is 48-52 mpg.

Overtaking:

when you know you need to quickly overtake turn mode selector to Sport. Just before you overtake select a lower 'gear'. The result is a quick overtake. The trick is not to not exceed the speed limit too much.

[NemesisUK]

10 hours ago, Hadrian said:

Thanks for the replies.

 

On a similar subject, this is the first car I've had with paddles on the steering wheel. I'm still not exactly sure what they do.

 

1 hour ago, ColinBarber said:

Really it is just a gimmick on the hybrid transmission, but if you put it in manual you can pretend to change gears using the paddles.

The main use is if you know you want to overtake you can 'drop down a gear' to bring up the engine revs beforehand so you don't have an acceleration delay when press down the throttle - you can do this in Drive, you don't need to be in manual mode.

Additionally one can restrict the gear range used by pulling the left paddle whilst in normal drive mode. This will stop the car changing up, good for engine braking and stop the box hunting up and down on hilly stretches. Just to add, in a hybrid doing the above will not use regenerative braking, so not so useful as in petrol/diesel ..

 

[Hadrian]

Thanks for the additional answers chaps. It's a bit of a steep learning curve :)

Getting there slowly though.

We had our first decent run out today.  Covering 85 miles it indicated  51mpg, which isn't bad considering it was up and down hill on "A" roads.

I did notice a fair bit of road noise, depending on the type of road surface. Probably down to the fairly low profile tyres ?

[NemesisUK]

Road noise is so dependant on the actual road surface!

Round my way we have quite a variety of finishes. My car can change from whisper quite to a significant howl.

I have wondered on what, presumably standardised , road surface they test tyres to give them their labelled rating? 

[ColinBarber]

26 minutes ago, NemesisUK said:

Road noise is so dependant on the actual road surface!

Round my way we have quite a variety of finishes. My car can change from whisper quite to a significant howl.

I have wondered on what, presumably standardised , road surface they test tyres to give them their labelled rating? 

It is a very smooth, fine grain surface. A grain size not really found in the UK. The sound measurement is also at the kerb rather than inside the vehicle and tyre manufacturers can design a tyre to throw more sound into the vehicle and away from the kerb to get a better rating. Essentially the tyre noise rating is completely useless to understand how much road noise will be inside your vehicle. 

[darrude]

Yesterday I drive from Birmingham airport back to Yorkshire. 100 miles M'way, 35 miles A/B roads. There was a large stretch of the M1 restricted to 60mph, so cruise set at 65, for a lot of journey, indicated 78mph rest of time. Without trying, I got 60mpg. So it is possible!

[Thackeray]

4 hours ago, darrude said:

Yesterday I drive from Birmingham airport back to Yorkshire. 100 miles M'way, 35 miles A/B roads. There was a large stretch of the M1 restricted to 60mph, so cruise set at 65, for a lot of journey, indicated 78mph rest of time. Without trying, I got 60mpg. So it is possible!

The temperature of 22C probably helped, too - no heating needed and not too much air conditioning.

If this had been my car the indicated 60.8 would have meant a real 55 or so, which is still pretty good for a 2.5 litre petrol engine. Does anyone else compare real mpg with indicated mpg? I'd be interested to know if a 9-10% discrepancy is standard on these cars or is mine an exception? A small amount of the discrepancy comes from tyres about half-worn. (That reduces the tyre size by nearly a centimetre and results in an overestimate of distance travelled.) But that probably doesn't make a great deal of difference.

 

[darrude]

2 hours ago, Thackeray said:

The temperature of 22C probably helped, too - no heating needed and not too much air conditioning.

If this had been my car the indicated 60.8 would have meant a real 55 or so, which is still pretty good for a 2.5 litre petrol engine. Does anyone else compare real mpg with indicated mpg? I'd be interested to know if a 9-10% discrepancy is standard on these cars or is mine an exception? A small amount of the discrepancy comes from tyres about half-worn. (That reduces the tyre size by nearly a centimetre and results in an overestimate of distance travelled.) But that probably doesn't make a great deal of difference.

 

I would never get close to that in winter, 53-54 maybe on that run. It was 29degs when passing Derby, so air con was on! I have compared real to actual (on winter tyres, if that makes a difference, it makes a greater Speedo difference to sat Nav) and mine was pretty close. Next time I fill up I'll do a check with the summers on.

 

On Monday mornings I make the reverse run at 4am, and really not hanging about, generally get 48-52, depending if I get slowed down with traffic, if that is helpful to the OP.

[ColinBarber]

3 hours ago, Thackeray said:

I'd be interested to know if a 9-10% discrepancy is standard on these cars or is mine an exception? A small amount of the discrepancy comes from tyres about half-worn. (That reduces the tyre size by nearly a centimetre and results in an overestimate of distance travelled.) But that probably doesn't make a great deal of difference.

Mine overestimated around 5 to 7%.

[BigChange]

My real mpg is always 10% less than the car's figure.  For what it is worth my annual real mpg for the past 2 years has been 47.61 and 47.41 for around 10,000 miles each year.  The closeness surprised me as it covers all sorts of roads, conditions and speeds both in UK and in C-Europe including those fabulous French/Swiss autoroutes.  No commuting though.  Those days are over !

[royoftherovers]

2 hours ago, BigChange said:

My real mpg is always 10% less than the car's figure.  For what it is worth my annual real mpg for the past 2 years has been 47.61 and 47.41 for around 10,000 miles each year.  The closeness surprised me as it covers all sorts of roads, conditions and speeds both in UK and in C-Europe including those fabulous French/Swiss autoroutes.  No commuting though.  Those days are over !

I`ve measured mine over the years and with different cars and my calculation shows 8% less than the vehicle figure. Same parish as Peter.

[Yamiuchi]

Had my car just under a month and daily commute in heavy traffic around 26 miles, currently getting 42-43mpg, that's with all interior settings on auto and heated seats on setting 1.

[Hadrian]

Thanks for the various replies. Driving on a variety of roads, motorways and A roads it's showing a touch over 53 mpg.

So not bad at all.

[Mr Vlad]

Road noise? What's that? I don't get any road noise in my car. Mind you I have my audio on louder than normal. You simply can't beat metal.