"Yet another MPG thread" - RX450h

[GSLV6]

I've had my F-Sport (3RX) for 3 or 4 weeks now and covered a fair few hundred miles, in fact, on my second or third tank of petrol now.

Temperatures have typically averaged about 8 degrees this past 3 weeks, so that will take a small toll om mpg, but for interest, these are the figures I'm returning:

Tyres all inflated to 2.4 Bar (cold):

Extra Urban, excluding motorways on runs over 10 miles:  35mpg

Short trips including urban (less than 10 miles):  27mpg

Motorway at a steady 70 miles per hour over 30 miles each trip:  31.5mpg

Overall tank average:  Tank #1:  28mpg; Best 36.7mpg (extra urban, 50 mile trip)

Tank#2:  30mpg average, Best again 36.7mpg extra urban (mix of motorway and A roads all within speed limits)

Nowhere near as good as the GS300 on the motorway (that returned 38mpg at a steady 70, with a best of 40mpg on one occasion)

Overall tank averages for GS300:  28mpg combined.

 

So, rather disappointingly, on the hope of hybrid tech reducing fuel bills, it seems that it makes little to no difference for the RX over the Mk3 GS, mostly due to the extra weight and frontal area.

If we take 70% of claimed economy, than take 5% off that for cooler weather, one could reasonably expect to see 30mpg combined this weather, and extra-urban  of about 33mpg.

The true stats show that this is pretty close to what I'm getting, so for all of you eager beavers looking at mpg figures as a way of persuading you over from your GS's....don't.  You won't get any better fuel economy, and far less on motorway trips in fact.

It will be interesting to see what the warmer weather brings, in terms of slight improvements, but it seems reasonable to take just 70% of manufacturer's claimed economy as what to expect in reality, IF you drive with a very light right boot.  Start to plant it, and those figures above will plummet.  How some seem to be getting better than this is a mystery, as I do drive with mechanical sympathy, and coast and glide where possible.

[rayaans]

Not bad at all though really for a 2 tonne SUV

My son's 2006 VW Polo 1.4 is barely getting 37mpg in winter. Only has 75hp and weighs 1 tonne lol, its reasonably peppy due to its gearing but hardly quick!

I tend to get a bit more on motorway trips than you though, I get roughly 35mpg at 70mph but Ive found cruise control seems to make MPG worse. My tyres are on 37psi all around.

Not taking depreciation into account, his car is costing me more to run than mine especially since the road tax is £185 on the Polo

[GSLV6]

35 is pretty good. You have a little more tyre pressure than me, but still, can't see 1 psi or so making almost 4mpg difference.  I'd be very happy with 35mpg motorway.  To be fair, there were a few longish hills thrown in as I was travelling between Gloucester and Monmouthshire on the M5, so had a few long drags uphill Bristol, a few downhill runs, then over the Severn Bridge, and the return trip, and staying within 70, 32.5 was the best I saw with 31.5 average for that return trip.  Not impressed.  I'l raise pressures a little more (but stay within recommended range) and see if that makes any difference.  It has made me think if there's something amiss sometimes with the hybrid system overall (ie too much frictional drag somewhere in the system) as a few people seem to be getting more like mid 30's average from their 3RXs.

[GSLV6]

Forgot to ask other RX owners if I may, what you are getting in real world combined driving, plus also motorway only?

Is it possible to also have two other bits of info?:

1.  Tyre pressures being run and

2) whether you're getting best results in ECO, Normal or Sports modes?  (or does it matter at all in fact?).

I use the EV whenever possible, brake gently and early, pulse and glide where possible, avoid accelerating when going up hills, and build speed up gently when on the flat.  Whatever I do, mixed driving in 10 plus miles is mid-30's if I'm lucky and longer cross country, about 37, but M-way is never more than 31 to 33 depending on gradient.  If this all sounds low, then perhaps there's a running issue that I need to address with Lexus, but when I mentioned mpg after shortly picking up the car, the usual party line of "book figures are never achievable" was All I could get from them.  I'm not daft, and know that, but real word overall average of 28 to 31mpg seems pretty poor. 

[rayaans]

15 minutes ago, GSLV6 said:

Forgot to ask other RX owners if I may, what you are getting in real world combined driving, plus also motorway only?

Is it possible to also have two other bits of info?:

1.  Tyre pressures being run and

2) whether you're getting best results in ECO, Normal or Sports modes?  (or does it matter at all in fact?).

I use the EV whenever possible, brake gently and early, pulse and glide where possible, avoid accelerating when going up hills, and build speed up gently when on the flat.  Whatever I do, mixed driving in 10 plus miles is mid-30's if I'm lucky and longer cross country, about 37, but M-way is never more than 31 to 33 depending on gradient.  If this all sounds low, then perhaps there's a running issue that I need to address with Lexus, but when I mentioned mpg after shortly picking up the car, the usual party line of "book figures are never achievable" was All I could get from them.  I'm not daft, and know that, but real word overall average of 28 to 31mpg seems pretty poor. 

Mine is almost always in Sport mode. However, the 35mpg on the motorway was in normal mode. Ive found it doesn't make much difference in MPG between ECO and normal and therefore find ECO a bit of a farce, especially as it ruins the power delivery

I also don't use EV mode as to me, it seems to raise MPG for a bit, then runs out of Battery and results in a bigger drop in MPG.

My driving style also appears different to yours. I try to keep momentum, hence I find myself accelerating down hills and gaining enough momentum to pull me up without any use of the accelerator (not always possible I know).

Ive also found it better for MPG to floor it to the desired speed and just hold it there.

I live in Yorkshire so hills are a huge problem for me but I dont think Im doing too bad all considering. I think the MPG would be much better if I did longer trips and had flat ground

[GSLV6]

Given your location, I'd say you're doing well!  I'll have to re-visit the basics as I'm not at all happy with 31.5 on Motorway trips, where speeds are between 65 and 70mph.  With the GS, having a lower profile meant it mattered less on speed and it delivered great economy on motorway mile munches.

[rayaans]

4 hours ago, GSLV6 said:

Given your location, I'd say you're doing well!  I'll have to re-visit the basics as I'm not at all happy with 31.5 on Motorway trips, where speeds are between 65 and 70mph.  With the GS, having a lower profile meant it mattered less on speed and it delivered great economy on motorway mile munches.

It is worth remembering though that the hybrid system is not great on the motorway anyway. Its mainly built for stop/start city traffic and low speeds. 

At 70mph, the RX (well the 3RXh anyway) will just be a 3.5l petrol engine lugging around hybrid components and batteries without any use apart from perhaps instant torque and charging up the Battery each time you coast.

I think the 4RX has had its motors modified to maintain motorway speed using the hybrid system.

[Silversalmon]

Hi guys, I'm a bit confused here regarding the driving modes. I have a 2010 Sei, there is the option of Eco mode and normal mode. Is Sport mode when you shift to the gear lever to manually hold gears? We have a CT200h and that has a sport mode but as far as I can see the RX doesnt? Am  I missing something???

Also, is ECO mode a waste of time, the salesman told me just to leave it in normal mode, eco was a waste of time. Glad to hear your thoughts.

 

Ed

[GSLV6]

8 hours ago, rayaans said:

It is worth remembering though that the hybrid system is not great on the motorway anyway. Its mainly built for stop/start city traffic and low speeds. 

At 70mph, the RX (well the 3RXh anyway) will just be a 3.5l petrol engine lugging around hybrid components and batteries without any use apart from perhaps instant torque and charging up the battery each time you coast.

I think the 4RX has had its motors modified to maintain motorway speed using the hybrid system.

Yes, I know that it runs as a 3.5l without batteries at motorway speeds, but was comparing it with your figures as you said you'd achieved 35mpg. If yours is a 4RX, I'd understand and say that's about right as an expectation of the differences between the two.  If yours was a 3RX, then there's something amiss!

[GSLV6]

34 minutes ago, Silversalmon said:

Hi guys, I'm a bit confused here regarding the driving modes. I have a 2010 Sei, there is the option of Eco mode and normal mode. Is Sport mode when you shift to the gear lever to manually hold gears? We have a CT200h and that has a sport mode but as far as I can see the RX doesnt? Am  I missing something???

Also, is ECO mode a waste of time, the salesman told me just to leave it in normal mode, eco was a waste of time. Glad to hear your thoughts.

 

Ed

I think that they changed the "modes" between models Edward.  With the 3RX, "normal" is just the start up mode, "Eco" has to be enabled via a button on the steering wheel, as does "Sport" which is also only available of F-Sport/Premium models.  Eco just switches things like air conditioning off to save a little more on fuel, especially from cold, but as you inevitably need to to de-humidify the windscreen these cold mornings, AC just ends up being used anyway.

[Silversalmon]

Thanks a lot Paul, I was beginning to think I was missing something. Think I'll just leave it in 'Normal' mode. Great forum for owners new to the RX range.

[julian1969]

12 hours ago, rayaans said:

It is worth remembering though that the hybrid system is not great on the motorway anyway. Its mainly built for stop/start city traffic and low speeds. 

At 70mph, the RX (well the 3RXh anyway) will just be a 3.5l petrol engine lugging around hybrid components and batteries without any use apart from perhaps instant torque and charging up the battery each time you coast.

I think the 4RX has had its motors modified to maintain motorway speed using the hybrid system.

I've done a few motorway jaunts in my short time with my 2RXh and I regularly see 'electric only' operation at motorway speeds (60-70 mph) - usually when either on the flat with very light throttle or downhill again on a light throttle. This is never sustained for longer than 30 or so seconds due to the inconsistency of my right foot or a change in the level of the road. I was very surprised when I first saw it as I was under the impression that electric operation was only up to 30mph or so.

 

 

 

[rayaans]

6 hours ago, GSLV6 said:

Yes, I know that it runs as a 3.5l without batteries at motorway speeds, but was comparing it with your figures as you said you'd achieved 35mpg. If yours is a 4RX, I'd understand and say that's about right as an expectation of the differences between the two.  If yours was a 3RX, then there's something amiss!

Mine is a 3RX and yep, 35mpg at 70mph. If I remember correctly though, it was on the M62 which had a large downhill section. But even still, I regularly get about 33mpg even when pushing on a bit.

7 hours ago, Silversalmon said:

Hi guys, I'm a bit confused here regarding the driving modes. I have a 2010 Sei, there is the option of Eco mode and normal mode. Is Sport mode when you shift to the gear lever to manually hold gears? We have a CT200h and that has a sport mode but as far as I can see the RX doesnt? Am  I missing something???

Also, is ECO mode a waste of time, the salesman told me just to leave it in normal mode, eco was a waste of time. Glad to hear your thoughts.

 

Ed

Sport mode was added to the facelift post-2012 RX's

[DanD]

9 hours ago, Silversalmon said:

Hi guys, I'm a bit confused here regarding the driving modes. I have a 2010 Sei, there is the option of Eco mode and normal mode. Is Sport mode when you shift to the gear lever to manually hold gears? We have a CT200h and that has a sport mode but as far as I can see the RX doesnt? Am  I missing something???

Also, is ECO mode a waste of time, the salesman told me just to leave it in normal mode, eco was a waste of time. Glad to hear your thoughts.

 

Ed

As per Rayaan's comment, no Sports mode on pre-facelift model. No EV button either.

I drive in Normal mode always, with climate control on all the time, and without giving economy any consideration. I probably do around 50% motorway, 30% cross country and 20% urban. I keep tyre pressure at 2 PSI above the manufacturer recommendation and run on Michelin Lattitude Tour HP (all have around 5mm of thread left). My average is between 28MPG and 29MPG.

[Funkyboy]

Wow that's really poor MPG when you consider the purchase price and ongoing service costs that's going to be a really exspensive car.

[rayaans]

1 hour ago, Funkyboy said:

Wow that's really poor MPG when you consider the purchase price and ongoing service costs that's going to be a really exspensive car.

Well sometimes you pay for the privilege of not having a diesel engine. 

TBH diesels don't do much more. My brother in law has a new Q7 and manages 35mpg and I've test driven the Volvo XC90 which got bang on 31mpg

The car is expensive to purchase anyway and I don't really fuss about mpg as its a very small amount compared to depreciation. Not to mention that fuel goes in expenses for me so hardly an issue

[Glover]

Re EV mode.  I've got a pre-facelift 450h Advance registered in May 2012 and I've got EV, which is accessed via the menu button on the steering wheel (right hand set of controls).  Is this because my car is a 2012 model albeit pre-facelift?

[Silversalmon]

I have a 2010 SEi and EV mode is selected via a menu on the steering wheel, it's just a faff having it there.

[DanD]

13 hours ago, Funkyboy said:

Wow that's really poor MPG when you consider the purchase price and ongoing service costs that's going to be a really exspensive car.

Is it really considering the size of the car, its weight and performance? - I don't think so. To be honest, when I buy a car, I intend to enjoy it to the full, without compromise. To me it is a shame - and a waste - to spend this kind of money and then spend years of ownership watching the pennies. I would rather buy a different car that is cheaper to run. Don't get me wrong, I do not like wasting money either. But it took me a while to save first for a RX400h and then RX450h and I want to enjoy my investment without regrets!

I still think that 28-29 MPG is pretty good if you were to compare it to a non-hybrid SUV offering similar levels of comfort and performance. And reliability!

Incidentally, a couple of weekends ago I took a NX300h from Winchester to Brighton and back, with 5 on board. Mostly motorway (M3 and M27) and some dual carriageway littered with roundabouts (A27). I was surprised that the fuel consumption was similar to my RX's. I put this down to the fact that the smaller engine had to work that much harder.

Loved the NX though, and I will replace the RX with one when the time comes as we no longer need the larger car.

[malcolmw]

I used to have a Range Rover Sport L494 with the 3L TurboDiesel engine. This has similar performance to the RX450h and similar weight etc. I got a real (forget what the on board computer said) MPG of about 29 - 30 mpg. I have averaged 32.7mpg in my 4th Gen RX450H so far in similar use.

[DanD]

Do you spend a lot of time on the M-way? - I wonder if my relatively poor MPG is more related to my time spent on M-ways rather than just my driving style although I admit to driving at between 75 and 80mph on motorways. Yes, it is above the speed limit and no, I don't feel bad about it.

[malcolmw]

My daily driving is on mixed roads but overall only about 5 - 10% motorway journeys. I typically drive 8 - 10 mile journeys on A and B class roads. I typically use "normal" mode.

On a longer trip to Cardiff at Christmas I used motorways/dual carriageways and recorded 34.5 mpg on the car computer (very accurate). I also typically do similar speeds to you on these roads. I am pretty satisfied with this.

BTW, one of my colleagues has an NX300h and I am pretty impressed with it.

[DanD]

Thanks Malcolm.

I too was impressed with the NX. It is a nice place to travel in and is very well put together. I thought size would be an issue, but it wasn't. I have some reservations with regards to performance, but after all it is only in comparison to the RX, so I am sure I would happily adapt and get used to it.

[GSLV6]

Well, as mileage grows, my average is slowly climbing up.  Best cross-country has been close to 44mpg now (so official figures CAN be had if on the flat!) and overall average is 28.5.  We have a lot of hills here though and from cold, it's fuel-sapping no matter what you drive. Our 2 litre Merc diesel estate managed about 36mpg overall and 32 to 36 locally so not  lot better. 

I've noticed that keeping speeds between 65 and 70 om motorways gets best economy.  Over 70 makes a big difference!

[DanD]

Out of curiosity I have decided to be a good boy - temporarily at least - and to amend my driving style to see if I could achieve better than my regular 28-29 MPG.

Over the past two weeks, I have adopted a more relaxed (!) approach to driving, using ECO mode in town or heavy traffic, and NORMAL mode the rest of the time. I have made a conscious effort not to drive over 75MPH on the M-way, and have continued to stick to the speed limit. I have also made an effort not to accelerate sharply and generally be more... fluid...

The result has been an average of 32 MPG, meaning a gain of 3-4 MPG. Worth the effort? Not sure...