Average mpg

[Joseph Bill]

Hi there, I have a 2013 gs300h premier and I am a bit disappointed  in the mpg I am getting from it. I am averaging around 38.0mpg to 39.0mpg which seems a bit low to me. The other thing that I have noticed is that the electric mode green light very rarely comes on and never comes on at over 30mpg. Can anyone give me any advice as I am new to Lexus. Cheers

 

[royoftherovers]

14 minutes ago, Joseph Bill said:

Hi there, I have a 2013 gs300h premier and I am a bit disappointed  in the mpg I am getting from it. I am averaging around 38.0mpg to 39.0mpg which seems a bit low to me. The other thing that I have noticed is that the electric mode green light very rarely comes on and never comes on at over 30mpg. Can anyone give me any advice as I am new to Lexus. Cheers

 

I`d be more than happy with that sort of average in my Gen 3 GS 450H.

Tell us about your typical journeys-length-long short,stop/start etc and we can then consider.

[johnatg]

I think that's about right. I get in the range 36 - 42mpg - the higher figure on long motorway runs. It's a big heavy car - I don't know that you can reasonably expect much more.

The Battery is pretty small by current hybrid car standards - the range on electric is very small - less than 2 miles and only at slow speed. The hybrid/traction Battery is there to boost acceleration.

Incidentally my view is that the fuel economy is down to the CVT gearbox, not the hybrid power set-up. For the size and weight of the car, I think you would be lucky to get 25-28mpg with a normal ice petrol power train, so to get 50% more is pretty good really. I'll expand on that sometime and explain why I think that and what my evidence is.

[johnatg]

So - why do I think that the fuel economy of Lexus GS/IS hybrids is more down to the CVT gearbox and less to the hybrid power train?

That's not the popular perception of hybrid cars but that's because of politics and marketing.

Let's like at what fuel consumption is - it is based on the transfer of chemical energy into kinetic energy in the vehicle. In hybrids, regenerative braking and spare engine power transfer some kinetic energy and chemical energy (petrol) into chemical energy in the traction Battery. That can then be used later to boost the kinetic energy in the vehicle, either by reducing the amount of petrol needed at any one time or to add to the power available from the engine to aid acceleration. But the hybrid Battery capacity is very small and you can watch its power reserve plummet quickly when called on for acceleration. (And equally you can watch its power available increase rapidly - even from near empty to near full when descending even a small hill.)

The amount of petrol being used at any one time depends on a number of things - the capacity and design of the engine, throttle opening and engine revs. Politicians and the green lobby want us to reduce the amount of petrol consumed and car manufacturers have gone about building this requirement into their ice vehicles in various ways. Current fashion is to use every small engines, which intrinsically use very little fuel on cruise. But then they add forced induction (mainly turbo charging but also supercharging or both) to increase power when needed for acceleration. Mondeos (RIP) and Range Rovers with 1 litre engines, anyone? I suspect that long term durability is very much an issue.

Lexus took a different approach - use a relatively big old lazy engine and run it at low revs and small throttle openings.

You don't need much power (and therefore petrol) to trundle a vehicle along at 30 mph - my wife's Seat Mii runs at about 1750 rpm at 30 mph - (that's not even on the power curve even on its little 1 litre engine) and is probably making about 20bhp or less. That's all you need - a GS is going to need a bit more but not much, until you open the throttle to accelerate and then the revs go up and the petrol starts pouring in. See current fuel consumption on the dash display! It's true that the amount of petrol required at that point is reduced by the boost available from the hybrid Battery, but see the comment about how small the hybrid Battery capacity is.

The revs all depend on gearing. The great benefit of a CVT gearbox is that it's always in the 'correct' gear. If you engage S mode on a motorway you can observe your engine revs - and you will find you can cruise at 70mph at about 1700 rpm on a level road. That is remarkable and not achievable with a manual or normal automatic gearbox unless you had many more available gears than is practical. (Not many people would want to drive an 18 speed manual as in Australian road trains etc) But at 1700 rpm and a moderate throttle opening you are using very little fuel - and that is why CVT gearboxes enable impressive fuel economy. You will observe 50-60 mpg instantaneously in cruise.

At 70mph on a motorway the hybrid Battery is doing little or nothing - but it will help some when you come to a hill or need to accelerate after a slow down.

Meanwhile, more recent hybrids (and plug-in hybrids) have a large capacity traction Battery and can achieve substantial range on that Battery. The GS and IS hybrid ranges are now 15-20 year old designs (from the drawing board) - you might argue that the origins are even older in the Prius. Electric vehicle technology has moved on by leaps and bounds so I'm afraid our cars are now rather outdated (but well proven technology). Which isn't to say that I won't be keeping my car for a long time yet!

[HensTeeth]

As others have said, it's going to depend very much on the kind of journeys you do. Short are always going to be lousy from an MPG perspective. I have a 4th gen GS450h, and my long term average is nearly 44mpg according to the computer, which I find a bit optimistic. 

However, a lot of that mileage is on relatively clear motorways, which balances the small amount of round-town trips I make. It is slowly becoming a no-car zone round here, so difficult are the authorities making it to move about by car, so most of the local trips are only to supermarkets, to bring children to school or activities. 

However, a fully loaded car with family on board, and a boot so full I was concerned it wouldn't shut yielded nearly 50mpg on a 700 mile round trip on motorways and A roads, with a bit of tootling at the holiday destination.

So I'd be very disappointed with a 300h to be getting what you are If I drove it under the same circumstances as the 450h.

Driving style plays a part though - I'll try to read the road ahead and never accelerate towards a red light or stationary traffic as a lot of people seem to do. I mostly (ahem) keep to the speed limits too. If your journeys require having to make rapid bursts of acceleration followed by braking to nip into gaps (I'm thinking central London or other large towns), it's not going to help, and would go a long way towards explaining the values you're getting. Honest John's real mpg site https://www.honestjohn.co.uk/realmpg/lexus/gs-2012/300h, shows quite a range of what people actually get.

[royoftherovers]

11 minutes ago, johnatg said:

So - why do I think that the fuel economy of Lexus GS/IS hybrids is more down to the CVT gearbox and less to the hybrid power train?

That's not the popular perception of hybrid cars but that's because of politics and marketing.

Let's like at what fuel consumption is - it is based on the transfer of chemical energy into kinetic energy in the vehicle. In hybrids, regenerative braking and spare engine power transfer some kinetic energy and chemical energy (petrol) into chemical energy in the traction battery. That can then be used later to boost the kinetic energy in the vehicle, either by reducing the amount of petrol needed at any one time or to add to the power available from the engine to aid acceleration. But the hybrid battery capacity is very small and you can watch its power reserve plummet quickly when called on for acceleration. (And equally you can watch its power available increase rapidly - even from near empty to near full when descending even a small hill.)

The amount of petrol being used at any one time depends on a number of things - the capacity and design of the engine, throttle opening and engine revs. Politicians and the green lobby want us to reduce the amount of petrol consumed and car manufacturers have gone about building this requirement into their ice vehicles in various ways. Current fashion is to use every small engines, which intrinsically use very little fuel on cruise. But then they add forced induction (mainly turbo charging but also supercharging or both) to increase power when needed for acceleration. Mondeos (RIP) and Range Rovers with 1 litre engines, anyone? I suspect that long term durability is very much an issue.

Lexus took a different approach - use a relatively big old lazy engine and run it at low revs and small throttle openings.

You don't need much power (and therefore petrol) to trundle a vehicle along at 30 mph - my wife's Seat Mii runs at about 1750 rpm at 30 mph - (that's not even on the power curve even on its little 1 litre engine) and is probably making about 20bhp or less. That's all you need - a GS is going to need a bit more but not much, until you open the throttle to accelerate and then the revs go up and the petrol starts pouring in. See current fuel consumption on the dash display! It's true that the amount of petrol required at that point is reduced by the boost available from the hybrid battery, but see the comment about how small the hybrid battery capacity is.

The revs all depend on gearing. The great benefit of a CVT gearbox is that it's always in the 'correct' gear. If you engage S mode on a motorway you can observe your engine revs - and you will find you can cruise at 70mph at about 1700 rpm on a level road. That is remarkable and not achievable with a manual or normal automatic gearbox unless you had many more available gears than is practical. (Not many people would want to drive an 18 speed manual as in Australian road trains etc) But at 1700 rpm and a moderate throttle opening you are using very little fuel - and that is why CVT gearboxes enable impressive fuel economy. You will observe 50-60 mpg instantaneously in cruise.

At 70mph on a motorway the hybrid battery is doing little or nothing - but it will help some when you come to a hill or need to accelerate after a slow down.

Meanwhile, more recent hybrids (and plug-in hybrids) have a large capacity traction battery and can achieve substantial range on that battery. The GS and IS hybrid ranges are now 15-20 year old designs (from the drawing board) - you might argue that the origins are even older in the Prius. Electric vehicle technology has moved on by leaps and bounds so I'm afraid our cars are now rather outdated (but well proven technology). Which isn't to say that I won't be keeping my car for a long time yet!

Have you noticed John, that the latest Generations of Rav4 and NX300h have drivers that are reporting fuel consumption figures approaching or exceeding 50mpg ? Possibly due to improved Drive Train Technology perhaps ?

[wharfhouse]

14 minutes ago, johnatg said:

So - why do I think that the fuel economy of Lexus GS/IS hybrids is more down to the CVT gearbox and less to the hybrid power train?

That's not the popular perception of hybrid cars but that's because of politics and marketing.

Let's like at what fuel consumption is - it is based on the transfer of chemical energy into kinetic energy in the vehicle. In hybrids, regenerative braking and spare engine power transfer some kinetic energy and chemical energy (petrol) into chemical energy in the traction battery. That can then be used later to boost the kinetic energy in the vehicle, either by reducing the amount of petrol needed at any one time or to add to the power available from the engine to aid acceleration. But the hybrid battery capacity is very small and you can watch its power reserve plummet quickly when called on for acceleration. (And equally you can watch its power available increase rapidly - even from near empty to near full when descending even a small hill.)

The amount of petrol being used at any one time depends on a number of things - the capacity and design of the engine, throttle opening and engine revs. Politicians and the green lobby want us to reduce the amount of petrol consumed and car manufacturers have gone about building this requirement into their ice vehicles in various ways. Current fashion is to use every small engines, which intrinsically use very little fuel on cruise. But then they add forced induction (mainly turbo charging but also supercharging or both) to increase power when needed for acceleration. Mondeos (RIP) and Range Rovers with 1 litre engines, anyone? I suspect that long term durability is very much an issue.

Lexus took a different approach - use a relatively big old lazy engine and run it at low revs and small throttle openings.

You don't need much power (and therefore petrol) to trundle a vehicle along at 30 mph - my wife's Seat Mii runs at about 1750 rpm at 30 mph - (that's not even on the power curve even on its little 1 litre engine) and is probably making about 20bhp or less. That's all you need - a GS is going to need a bit more but not much, until you open the throttle to accelerate and then the revs go up and the petrol starts pouring in. See current fuel consumption on the dash display! It's true that the amount of petrol required at that point is reduced by the boost available from the hybrid battery, but see the comment about how small the hybrid battery capacity is.

The revs all depend on gearing. The great benefit of a CVT gearbox is that it's always in the 'correct' gear. If you engage S mode on a motorway you can observe your engine revs - and you will find you can cruise at 70mph at about 1700 rpm on a level road. That is remarkable and not achievable with a manual or normal automatic gearbox unless you had many more available gears than is practical. (Not many people would want to drive an 18 speed manual as in Australian road trains etc) But at 1700 rpm and a moderate throttle opening you are using very little fuel - and that is why CVT gearboxes enable impressive fuel economy. You will observe 50-60 mpg instantaneously in cruise.

At 70mph on a motorway the hybrid battery is doing little or nothing - but it will help some when you come to a hill or need to accelerate after a slow down.

Meanwhile, more recent hybrids (and plug-in hybrids) have a large capacity traction battery and can achieve substantial range on that battery. The GS and IS hybrid ranges are now 15-20 year old designs (from the drawing board) - you might argue that the origins are even older in the Prius. Electric vehicle technology has moved on by leaps and bounds so I'm afraid our cars are now rather outdated (but well proven technology). Which isn't to say that I won't be keeping my car for a long time yet!

And more so that the ICE in a Toyota / Lexus hybrid such as the 300h power train runs the Atkinson cycle rather than the usual ICE Otto cycle. The Atkinson cycle gives much better mpg but has little low down torque. So the electric motor fills in this low down torque (electric delivering immediate torque) so the ICE Atkinson cycle can then be run for efficency. The e-cvt is a great piece of engineering giving flexible power split maximising best fuel economy for the ICE for the demands made in terms of power and all in an incredibly simple robust package, especially compared to normal auto boxes. 

[wharfhouse]

3 minutes ago, royoftherovers said:

Have you noticed John, that the latest Generations of Rav4 and NX300h have drivers that are reporting fuel consumption figures approaching or exceeding 50mpg ? Possibly due to improved Drive Train Technology perhaps ?

It's worth mentioning that my 2014 IS 300h still delivers an average of 48mpg on the car computer and on a long run 50+ mpg is easily achievable (and at national speed limits) without any special driving techniques over and above what one would do naturally to keep fuel consumption down. When I've had a courtesy car there is an improvement in the latest hybrid drive train for fuel consumption but it's not a huge leap. Good fuel consumption always comes down to basic driving style of accelerating positively and smoothly, carrying speed as long as possible and forward thinking for slowing down and braking gradually to max out any regeneration. This works of course for any car but for the hybrid power train is particularly beneficial. However accelerate and brake harshly and last minute will see the mpg reduce dramatically as the hybrid elements aren't able to contribute much and so traditional ICE mpg will then prevail. IMHO driving style therefore still has probably more impact on the fuel consumption than the later drive trains. 

[Joseph Bill]

11 hours ago, royoftherovers said:

I`d be more than happy with that sort of average in my Gen 3 GS 450H.

Tell us about your typical journeys-length-long short,stop/start etc and we can then consider.

Thanks for the reply. I have very little experience of Lexus hybrid, the only other hybrid I have ever driven is  a brand new Hyundai Tucson N line  and my average was 46mpg in that but of course it is a few newer more modern vehicle. I do mostly short journeys  but on my recent holiday to South wales I did get 46mpg

[royoftherovers]

39 minutes ago, Joseph Bill said:

Thanks for the reply. I have very little experience of Lexus hybrid, the only other hybrid I have ever driven is  a brand new Hyundai Tucson N line  and my average was 46mpg in that but of course it is a few newer more modern vehicle. I do mostly short journeys  but on my recent holiday to South wales I did get 46mpg

Hi Joseph,

Short journeys will lead to neither good fuel economy nor Hybrid Battery storage of power.The car will cut out its engine only when there is sufficient power in the Hybrid Battery to move the vehicle along on Hybrid Power alone.

See this video and search for more on Youtube.

 

[Las Palmas]

Hi Joseph,

The GS is a heavy car and that mean it will need more to move than a lighter. The fuel consumption is in eyes of all other on the forum (incl. myself) absolutely fine.

We have a CT, micro-Lexus and though we are happy with it, fuel consumption (about the same as you have in the GS) is not what promised from factory. All car companies come with impossible to reach fuel efficiency in normal day to day life.

If we drive from where we live to south of the island and back on the highway, which is mostly pancake-flat we can have 4.8L/100km, but as we drive around in the hilly, mountain island we have fuel consumption like you have in a far heavier car. When driving to market to get fresh vegetables, 1000 meter above sea level, which is where we live, petrol engine is not having a break, but is guzzling fuel constant; when then driving down hybrid Battery is full after a few km and when it is full all brake energy is wasted. EV light is on all the way down, but not helping.

6.2L/100km is what we get for living on a mountain island. Where we live, I believe a car that did not have the weight of the hybrid Battery would be more fuel efficient. Before the CT we had a Golf 2.0tdi DSG that was using only 5.2L/100km. Here a plug-in hybrid might be worse, though it has a larger Battery you can fill with (expensive at this time) electricity and have it help you uphill, that same Battery will also be much heavier and thus need more fuel to get uphill, while it will be full on the way down, much before we come home.

[Ala Larj]

13 hours ago, Joseph Bill said:

Hi there, I have a 2013 gs300h premier and I am a bit disappointed  in the mpg I am getting from it. I am averaging around 38.0mpg to 39.0mpg which seems a bit low to me. The other thing that I have noticed is that the electric mode green light very rarely comes on and never comes on at over 30mpg. Can anyone give me any advice as I am new to Lexus. Cheers

 

Is that calculated or from the on board computer? I have a 2014 GS300h premier and according to the computer have averaged 44.7mpg over five years of ownership. That has been on a variety of journeys from the occasional 400 miles plus to short shopping trips. Over the last four years it’s mainly been on the quiet Lincolnshire roads. Not bad for a 2.5 litre behemoth! Our second car is a 2008 1.4 litre Honda jazz which has averaged 42.2 over a slightly longer period than the Lexus. I’m happy with the economy I’m getting from the Lexus. I drive it how I expect it to be driven. Relaxing cruising with the occasional burst of speed when required. I’m also old enough to remember my Vanden Plas 1300 and was well chuffed when I managed 28 mpg!

[Initial P]

I find it better to go by tank range what do you 300h owners get on a full tank?

[Ala Larj]

3 hours ago, Initial P said:

I find it better to go by tank range what do you 300h owners get on a full tank?

Life’s too short to get a spreadsheet out! 😉

[Vadim]

On 9/25/2022 at 9:33 AM, Joseph Bill said:

Hi there, I have a 2013 gs300h premier and I am a bit disappointed  in the mpg I am getting from it. I am averaging around 38.0mpg to 39.0mpg which seems a bit low to me. The other thing that I have noticed is that the electric mode green light very rarely comes on and never comes on at over 30mpg. Can anyone give me any advice as I am new to Lexus. Cheers

 

Welcome to real world )

[ColinBarber]

On 9/25/2022 at 12:08 PM, johnatg said:

and you will find you can cruise at 70mph at about 1700 rpm on a level road. That is remarkable and not achievable with a manual or normal automatic gearbox unless you had many more available gears than is practical.

My GS F would happily cruise below 1800 rpm at a real 70 mph (not just indicated) in 8th gear 🙂 

 

But yes I agree, the combination of CVT and Atkinson cycle engine creates the efficiency, the electric motor is there to compensate for the lack of torque from the Atkinson cycle engine when you need it. Then in town you have a sophisticated start/stop system to save fuel.