Does This Mpg Sound Right

[mikesands]

Just picked up my RX400H today (2009 model) and I think I'm really going to like it. But today I have been getting about 33mpg round town and about 26 on a steady run at 70mph on dual carriageway. Does this seem right?

Mike

[ISJason]

hi, if u don't go heavy on the gas u shud get around 35 mpg on the motorway.

[kalibur]

Check your tire pressure is equal on all four wheels. Doing 70 on cruise control I get 30+ but if one wheel pressure is low I get 25-26ish.

[ColinBarber]

at 70 mph you should be able to get around 30mpg. As already stated make sure the tyre pressures are correct. You do have to remember that the hybrid system has very little affect when running at high speed so you shouldn't expect better mpg than a normal 3.3l V6 SUV.

[ISJason]

Colin, i doubt that is correct, if i may be so bold, I regularily get 35 to 37 mpg on the Mway.

So it says in another topic on this forum, the hybrid motors can come in at any speed and power the car, taking over from or

assisting the petrol engine, so aiding feul economy.

[ColinBarber]

I personally have never got over 33mpg indicated on a motorway and it is normally sub 30mpg. You also have to remember that the indicated mpg is normally always 2 or 3 mpg more than it actually is.

Yes the motors will come on to assist on occasion, but overall it has very little affect because the engine will never cut out at those speeds and there is little opportunity to recover any energy because you aren't braking.

This is all backed up by the official mpg figures, with the combined figure being no better than the urban figure.

35 to 37 mpg sounds impressive. What tyres do you have?

[mikesands]

Hmmmm .... I think motorway mpg with this car may end up being a bit disappointing from what you are saying. My LS430 used to return 30mpg genuine (measured by tank fillups) and that was cruising at 78mph. Sounds like the RX400h will be nearer 25mpg at 78

Mike

[Duncan Roberts]

Depends how you drive but in principle itr is probably OK

[ColinBarber]

Mike I think you should be able get closer to 30mpg but you have to remember it is an SUV and doesn't cut through the air like an LS and possibly has a bit more rolling resistance from wider tyres, depending on what is fitted.

[mikesands]

Good points Colin I think the LS had 225s and the RX has 235s. And I think the LS lowered itself on its air suspension when at speed (it's even lower at a standstill at the moment :D )

Just got 27.9mpg tonight on an 80 mile trip (almost all motorway)

Mike

[fulmar]

My RX 450h is a month old. I'm getting about 40 mpg in suburban driving. I've not yet done a long trip on the motorway.

[fezman]

Just collected my 450h this week (2010) and on a 300 mile motorway run averaged 33mpg, ave speed probably about 73/4. What i did notice was that giving it a bit of boot quickly dropped the mpg for the whole trip, i.e. was doing about 35 mpg, gave it full throttle for about 10-15 secs to overtake a load of slow moving vehicles and reduced to 33mpg.

So not too far from my IS 220d which managed about 37/8 at similar speeds.

About 5 miles from home 0 reset the mpg, and on mostly A roads managed around 38. This is much better than the IS which gave a woeful 31/2

[CJHYBRID]

I am amazed so far with the fuel economy with although only done 600 miles so far. My Rover was a 1968 cc CDTI auto and my daily work commute is 14 miles which is down hill one way and up the back with a couple of miles through towns and villages.

The Rover averaged 32 mpg and so far Lexi ( Have named every car sknce I was 17) has averaged 33.8 mpg.

On runs such as the second day when I did a 300 mile tester on all kinds of roadsmincluding a stint to Levington on the North Yorks Moors I acheived 35.7. Any one who has been to Levington and the surrounding area will understand that this is pretty testing conditions for a car particularly in torrential rain.

I am still thinking of adding ZX1 anti friction additive. Am new to the technical side of the car so want to make sure gear box and engine oil are totally separate before adding as not 100% sure how the Cvt gearbox works hence anti friction may not be a good idea.

In the engine however I am confident as my last two Rovers each coveredmin excess of 190000 miles and the engines were still going strong at point of sale.

Best regards

Chris

[fulmar]

I have just done a 500 mile trip in my RX450h, mainly on Motorways and dual carriage A34. Average fuel consumption = 37.9 mpg.

I noticed that at 70 mph the engine is running all the time and from time to time it charges the HV Battery, and also from time to time the Battery joins the engine in driving the front wheels.

Acceleration feels similar to my 2001 GS300, but steering 'feel' is much better in the RX and of course the fuel consumption is some 20% lower. But I prefer the ride in the GS.

[mburstyn]

I've posted here before about mpg, but here goes. My daily run is about 18 miles - 1 mile to dual carriageway, 16 miles, then 1 mile from dual carriageway. The dc has a 50 mph limit and lots of cameras so i just wind my 400h up to 50, set the cruise control and leave it at that. On a good day I have seen 45+ mpg and will always get 40+ unless stuck for a long time in traffic

.

[lurch]

Well that looks good, I've just been down to Heathrow from mine a round trip of 350 miles and averaged 36 mpg which I was well pleased with as I did give her a bit of wellie at times. Mine has done about the same miles at 42,000 .