Fuel Economy

Platypus · January 19, 2014

Platypus, and thats where the German cars are better (i.e. more economical), which is why more of them sell (see thread in IS250 section). Lexus will NEVER say that hybrids aren't as good on the motorway as diesels. A hybrid will typically be carrying the weight of the batteries and motors without them doing much unless you drive totally differently - i.e. lift at every opportunity, coast, gently apply throttle to try and get some thrust with the motor only etc etc. It would be come tedious, and you would have to drop speeds considerably to get that 60+ mpg on a motorway with a hybrid.

There is still a much bigger difference between what a diesel will get MPG wise in "the real world" on a motor way compared to a hybrid in relation to the govt test figures. The CO2 tests only help to sell cars against a company and BIK/Tax needs. The whole thing is a bit of a sham.

At motorway legal speeds my GS250 will easily achieve between 35 and 37mpg consistently. My old 525d BMW (6 Cyl 3.0l Auto) would easily get 45-47mpg, and a friends new shape 320d will hit 53-55mpg without trying.

Silver Arrow,

David from Staffordshire gets 48mpg on the M6 without hypermiling - that would be my holy grail. So, if I take your friend's BMW320D's real-world figure of 53mpg and compare it with David's F-sport's real-world figure of 48mpg, apply a correction factor for calorific value of the fuel of 0.9 (petrol 9.7kWh, diesel 10.7kWh), then David's F-sport is almost just as energy-efficient. Granted, I'd have to invest more effort with my pulse and coast technique, but I'm also guessing your friend's Beemer is a stick-shift, so he'd probably be expending energy on his clutch and gear-stick technique.

It's a pity though, that the difference in energy content of petrol and diesel is not reflected in their price.

As far as CO2 emissions go, the beemer would be pumping out 142g/km as opposed to the Lexus' 136g/km

But 45mpg would do me fine, which I was getting around August/September.

Silver Arrow · January 19, 2014

Only commenting on the first few posts, where people are seeing 41-48mpg

PS - 320d SE, 8 Speed Auto (not an ED model)

Richard1200 · February 8, 2014

Since starting this topic last October I have not done any long runs, all short journeys to shops etc. now on 2200miles and averaging 39.6 mpg so very pleased as my V6 IS would have been doing about 21mpg at this time of year. I forget to look at the fuel gauge. The car came full when new and I think I have ony filled up 3 times.

Still very happy with my car, no regrets at all. Still not seen another one on the road!!!!!

DJP · February 8, 2014

I have virtually halved my petrol expenditure.

F Sport Marcus · February 10, 2014

First day in and 400miles of mainly motorway at sensible speeds in eco and 51.2mpg.

Tel · February 11, 2014

What Car have done Real World Fuel Consumption Tests with the 300h & 4 German Marques & the Lexus wins easily------I would have posted the Link but only have a E in IT!

Tel

jasone · April 2, 2014

Only getting 41 mpg. I do roughly 70 miles / day. 10-15 miles in slow traffic and the rest at 70 mph. Is this what I should be expecting? Not the end of the world but was expecting the other side of 50 as the website claims combined 60 mpg.

Richard1200 · April 2, 2014

I am averaging around 46mpg. Mostly short journeys to shops etc, very little motorway, occasional longer A road journeys. Getting better now the weather is warming up. I am very pleased as my my previous IS did around 22mpg in the winter and 25 ish in the summer.

DJP · April 2, 2014

I am averaging around 46mpg. Mostly short journeys to shops etc, very little motorway, occasional longer A road journeys. Getting better now the weather is warming up. I am very pleased as my my previous IS did around 22mpg in the winter and 25 ish in the summer.

Richard, do you drive mainly in "normal" mode? I do and am struggling to break the 40 mpg and am wondering if I might be better served by keeping it in "eco". I filled up the other day and am going to try "eco" for a tank so we will see.

Richard1200 · April 2, 2014

I am averaging around 46mpg. Mostly short journeys to shops etc, very little motorway, occasional longer A road journeys. Getting better now the weather is warming up. I am very pleased as my my previous IS did around 22mpg in the winter and 25 ish in the summer.
Richard, do you drive mainly in "normal" mode? I do and am struggling to break the 40 mpg and am wondering if I might be better served by keeping it in "eco". I filled up the other day and am going to try "eco" for a tank so we will see.

Has been in ECO mode since I bought it. Did try sport the other day with the paddle shift and did it ever fly. I bought the car for the luxury, economy and at my time of life very sedate driving.

DJP · April 2, 2014

I am averaging around 46mpg. Mostly short journeys to shops etc, very little motorway, occasional longer A road journeys. Getting better now the weather is warming up. I am very pleased as my my previous IS did around 22mpg in the winter and 25 ish in the summer.
Richard, do you drive mainly in "normal" mode? I do and am struggling to break the 40 mpg and am wondering if I might be better served by keeping it in "eco". I filled up the other day and am going to try "eco" for a tank so we will see.

Has been in ECO mode since I bought it. Did try sport the other day with the paddle shift and did it ever fly. I bought the car for the luxury, economy and at my time of life very sedate driving.

You can't be that old, you're posting on a tinternet forum! Is that bike avatar not yours then??

PST · April 2, 2014

I started with 46 mpg (car said 48 mpg), now up to 53 mpg (car said 56 mpg). (I have the SE)

I assume the improvement is down to weather warming up and car running in.

Been in ECO mostly, with only using sport now and again, driving in eco does make sport feel really quick.

Been doing the get up to speed then blip the throttle to settle the car into higher mpg technique I had heard on here.

Also been keeping it in electric as some kind of challenge, gives me something to do when driving.

I've also found pressing the ev button on each start and doing the first bit in pure electric gives me a better mpg over the trip.

I also pumped my tyres to 39 as opposed to the delivery 36 pressures.

F Sport Marcus · April 4, 2014

The Luxury I had with 6k on the clock I could easily get >50mpg and now with a new F Sport I'm getting at best mid 40's. Probably improve as it beds in..

Steve44 · April 5, 2014

Just been looking at tyres and noticed there is a big difference between brands for the displayed regulation economy mark. Some such as Yokohama and Bridgestone are band F and G, whereas Pirrelli and Michelin have some in band B and C. What brands of tyre do Lexus fit as OEM?

DJP · April 5, 2014

My F Sport has Bridgestone Turanza ER 33's. I have no idea whether they are good, bad or indifferent. It was suggested in another thread that they are not the best tyres for economy. I must admit I have just trusted Lexus to put good tyres on, maybe I shouldn't and should do some research for when they need replacing. Further admission, I don't even know how many miles I should expect from them either.

Steve44 · April 6, 2014

just had a compare on mytyres.co.uk. Bridgestone ER33 255/35/18 is rated F for economy and C for Wet Grip. Also middle of the range 71dB for noise.

http://www.mytyres.co.uk/cgi-bin/rshop.pl?dsco=110&cart_id=84790383.110.8461&Breite=255&Quer=35&Felge=18&Speed=Y&Load=90&kategorie=6&Marke=Bridgestone&ranzahl=&tyre_for=&Herst=Bridgestone&sort_by=Lable_1roll&rsmFahrzeugart=PKW&homologation=&Label=F-C-71-2&details=Ordern&typ=R-248376

As a comparison, the Dunlop SportMaxx RT is rated C for economy, A for wet grip and noise is rated at 68dB, and it's cheaper!

http://www.mytyres.co.uk/cgi-bin/rshop.pl?dsco=110&cart_id=84790383.110.8461&Breite=255&Quer=35&Felge=18&Speed=Y&Load=&kategorie=6&Marke=&ranzahl=&tyre_for=&sort_by=Lable_1roll&rsmFahrzeugart=PKW&homologation=&Label=C-A-68-1&details=Ordern&typ=D-119960

Apparently the difference between a band A rated tyre and a Band G for fuel economy is 7.5%. And 3dB less noise is half the noise level on the logarithmic scale.

Food for thought

DJP · April 6, 2014

That's very interesting. My IS250 had Bridgestone Turanzas as well, presumably a Lexus preferred tyre. One wonders why and if others have any views? Might be worth you asking your dealer, as you haven't taken delivery yet.

Lexus Si · April 6, 2014

F-sport. 42mpg for the first 2000 miles now up to 45mpg after 6000 miles according to the computer - being fairly sensible on motorways mostly. Just did 1200 miles with a roof box on and averaged 35mpg, mostly Autoroute and some mountains. Will definitely check out alternate tyres when the time comes so thanks for the tip. I wonder why Lexus thought it necessary to fit 255's at the rear. Seems excessive.

Steve44 · April 6, 2014

That bodes well LexusSI. 255 width tyres do seem excessive given the power output is identical on all IS hybrid models.

rayaans · April 15, 2014

That bodes well LexusSI. 255 width tyres do seem excessive given the power output is identical on all IS hybrid models.

Right guys, you are simply not trying hard enough! Whatcar have an IS300h F Sport on their long term testing fleet and after a short meeting with a fleet driving trainer, theyve managed to get 56.9mpg! Thats up from their average of 45mpg! Just goes to show that it can be done!

On a side note, I just averaged 47mpg in my RX450h! Crazy traffic on a slip road today and then on another road into town! Managed to do 10 miles just on EV mode due to a long downhill stretch and then constant charging of the Battery while braking in very slow traffic! 10 miles in an hour! LOL