New RX450h Owner Questions (Oh No)

[Lost it]

Well. I have a year 2000 Jaguar S type 4.0 V8. On a "run" using fairly clear roads (A3, M25, A1) to Peterborough I can get anything up to 28mpg at usual motorway speeds. But it's usually around the 25mpg mark. I don't hammer it, a big lazy 4 litre V8 you don't need to. I like the sound it makes...But when I do I can glance at the onboard mpg indicator and watch it drop to circa 12mpg. There's a price to pay if you want to use it. I don't expect anything else. Wide rubber, very grippy.

I used my wife's Ford Fiesta 1.4 auto to go to work one day last week, pre MOT because she doesn't use it much, it did just over 38mpg.

I also have a 2004 3.0 V6 Jaguar XJ6. It has the Jaguar version of the Ford Duratec V6 3 litre that makes 240bhp. Same journey, much lighter car being aluminium bodied, it will give me 34mpg if I can coax it into 6th gear which means it will be breaking the speed limit slightly.If not it's 29-30 mpg. But it does have wide and grippy tyres on it.

And I have a 2001 model Mini 1 1600 which struggles to do anywhere near 40mpg, because frankly I drive it like I stole it. That's what they are for. In the right conditions.

And now I have my 2000 model Lexus RX300 that is fitted with more or less commercial truck tyres that were cheap but have a good wet weather rating. That's what they feel like, very stiff sidewalls and I'm getting circa 28mpg off her and I'm happy at that because like I said, it's a big, heavy, not very aerodynamic lump. And I really want to try a Hybrid not because of the fuel economy, but because I have never driven one. Do I take the risk of simply buying an older one to see how I get on with it? Or waste peoples time test driving ones for sale... Not that kind of chap if I'm honest.

You see I didn't know the engine only ran if the Battery asked for it. I didn't know that you cannot just start the engine and drive off. There's a lot I don't know.

I have driven a Leaf and a Volt(?) and they were a little strange if I'm honest.

When I use my 2015 Honda VFR FE to go to work at Watford, I get an average of 58mpg. Like I try and get across, it's horses for courses. I pulled up behind a really nice RX400h at the turn off onto the M25 yesterday on my way home, it had private plates and I was about to ask the driver about it when the lights changed... That's what I need to do, look out for an owner whilst I'm at work (I'm building a new Aldi at Century Park in Watford) who has pulled up in the car park and see if they don't mind if I ask a few questions. I sort of believe that Lexus owners will be as proud of their cars as the average older Jaguar owner. And most bikers if I'm honest.

My daughter has a 2018 model Renault Twingo .9 litre turbo thing. Even with stop start she cannot get anywhere near the manufacturer figure for fuel economy, she gets high 40's.

The above is why I don't expect to buy a large engined luxury barge and get good mileage. Manufacturers figures are done in a lab, not on a road. Don't know why they bother with them if I'm blunt. Not a useful guide at all.

[Zotto]

It's not a topic related to lab tests, the main reason (and not the only one) because hybrids make good mpg is regenerative braking, every time you need to diminish your speed kinetic energy is  recovered and stored in HV Battery pack to be used later on instead of being wasted, so even a unaware of hypermiling techniques driver may obtain better mpg.

[Lost it]

I had a look on utube last night. Very clever. I have to try one.

[Barry14UK]

More realistic MPG figures for many cars as they are based on drivers experience, can be found on the 'Honest John' site.

When I bought my RX 450 it was showing 32.6 MPG. Very short runs produce about 26 MPG and on a run I get about about 34. driven up to speed limits. So overall getting about 30.  However, North Devon is very hilly so I think this affects detrimentally. The regeneration does not entirely offset the extra fuel to climb the hills.

As regards the CVT transmission, I have got used to the extra noise this makes on heavy acceleration although prefer a conventional auto box.but this was not a deal breaker.

[olliesgrandad]

5 hours ago, Barry14UK said:

More realistic MPG figures for many cars as they are based on drivers experience, can be found on the 'Honest John' site.

When I bought my RX 450 it was showing 32.6 MPG. Very short runs produce about 26 MPG and on a run I get about about 34. driven up to speed limits. So overall getting about 30.  However, North Devon is very hilly so I think this affects detrimentally. The regeneration does not entirely offset the extra fuel to climb the hills.

As regards the CVT transmission, I have got used to the extra noise this makes on heavy acceleration although prefer a conventional auto box.but this was not a deal breaker.

Your mpg sounds spot on. I do a mixture of motorway and rural driving and my phone app over 17000 miles gives an average of 32.6.

Personally I prefer the CVT to a conventional auto. 

[Lost it]

I used my RX300 for two days this week to get to Watford and home, a round trip of 180 miles, AM it's off Hayling Island, up the A3, the M25 to the Watford turn off so mainly cruising speeds, a bit of traffic at the Watford end circa 07:30. Home it's a reverse run, but this time the M25 is pretty much a stop start fest with average speeds of 25mph I guess? But normal motorway speeeds realistically, I have to use cruise because it seems to love being around the 80 Klepton mark, and I know in many cases Cruise isn't the best way to use the motor.

I usually use my red Honda VFR800 for the commmute, it's more fun, and knocks hours off the journey time literally.

Anyway, the onboard mpg thing shows 26.5mpg. No idea how accurate it is, but it was on 27.8mpg when I got here on the first day, the return journey with the M25 rush hour traffic knocked about 1mpg off.

Which is pretty much around what I expected. So I think once I've worn this one out, I will have to look at a Hybrid.

[Zotto]

A  good advice to obtain better mpg in short journeys with hybrids is to let 1st warming phase of thermal motor not moving or going very slow (under 15 mph); in summer it takes 1 minute or less.

So the procedure is: 

push start button (in P)

press  for a moment throttle pedal to force engine start (it goes at 1000-1200 rpm)

when engine goes off start moving car.

 

Why this routine? because in short routes, the warming of thermal engine is the most petrol consuming phase and affects total mpg result.

Of course, if you are in real hurry you can ignore advice 🙂

[Lost it]

So in effect you are saying warm it up before starting your journey. I always have done this, never believed in cold start pull away theories.

[Zotto]

Warming up before starting journey or moving very slow at first minute is a good advice for all engines. 😃

[rayaans]

Except the advice nowadays is not to warm the vehicle up for more than 30s. They warm up quicker during normal driving anyway

[Herbie]

1 minute ago, rayaans said:

Except the advice nowadays is not to warm the vehicle up for more than 30s. They warm up quicker during normal driving anyway

You just beat me to it 

[jpower]

Back to the towbar - me and my friend fitted the towbar on my X5, he kindly offered to do it again, he's more the know how, I'm just the second pair of hands.

How do I know is my rx450h has self levelling suspension? If there something obvious to tell me? As the tower option is different.

[Gliderpilot]

2 hours ago, jpower said:

Back to the towbar - me and my friend fitted the towbar on my X5, he kindly offered to do it again, he's more the know how, I'm just the second pair of hands.

How do I know is my rx450h has self levelling suspension? If there something obvious to tell me? As the tower option is different.

by "self levelling" they mean air suspension, if you've got it you will know, there are no springs visible and there is an adjustment switch low down next to the front door. If you have air suspension then good luck getting a towbar as only the Westfalia detachable bar will fit your model,(this is what Lexus fit) and there are none in the country at the moment. I'm trying to get one for mine from PF Jones but due to a merger or something between Witter and Westfalia there are none available.

[jpower]

19 hours ago, Gliderpilot said:

by "self levelling" they mean air suspension, if you've got it you will know, there are no springs visible and there is an adjustment switch low down next to the front door. If you have air suspension then good luck getting a towbar as only the Westfalia detachable bar will fit your model,(this is what Lexus fit) and there are none in the country at the moment. I'm trying to get one for mine from PF Jones but due to a merger or something between Witter and Westfalia there are none available.

You may want to order right now, the detachable has just come back in stock, its more expensive then I thought, with electrics I wanted was coming out at £436 so I am going to wait till the non-detachable swan neck is available think that's about £270

[Gliderpilot]

43 minutes ago, jpower said:

You may want to order right now, the detachable has just come back in stock, its more expensive then I thought, with electrics I wanted was coming out at £436 so I am going to wait till the non-detachable swan neck is available think that's about £270

Thanks for the heads up, just ordered one from PF Jones to be fitted at my home with a dedicated 13 pin wiring loom.

[Lost it]

On 7/3/2019 at 10:55 PM, rayaans said:

Except the advice nowadays is not to warm the vehicle up for more than 30s. They warm up quicker during normal driving anyway

Because it helps the manufacturers give unrealistic figures for mpg on urban cycles. Not because it "helps the engine warm up quicker". The first few seconds of an engine start cause the most wear to your engine. You are worst case dragging oil at sub zero tempratures from the sump, it's usually thick enough in those conditions that there will be a degree of oil bypass in the oil filter, then you are sending the thick and turgid oil to everything else that is cold and expecting it to lubicate the lot immediately. Then you drive it away... Worst thing you can do. At least give the gearbox a chance to lube everything, and the engine oil a chance to reach the parts that need it's qualities.

Lots of stuff on You Tube about what oil is like when it's cold. If you think after watching this that starting you car and driving away immediately from a cold start is ok, well you have more belief than I ever will.

Anyway.. I thought the Hybrids started from stationary on Battery and only started the motor when the extra grunt was required?

 

[rayaans]

9 minutes ago, Lost it said:

Because it helps the manufacturers give unrealistic figures for mpg on urban cycles. Not because it "helps the engine warm up quicker". The first few seconds of an engine start cause the most wear to your engine. You are worst case dragging oil at sub zero tempratures from the sump, it's usually thick enough in those conditions that there will be a degree of oil bypass in the oil filter, then you are sending the thick and turgid oil to everything else that is cold and expecting it to lubicate the lot immediately. Then you drive it away... Worst thing you can do. At least give the gearbox a chance to lube everything, and the engine oil a chance to reach the parts that need it's qualities.

Lots of stuff on You Tube about what oil is like when it's cold. If you think after watching this that starting you car and driving away immediately from a cold start is ok, well you have more belief than I ever will.

Anyway.. I thought the Hybrids started from stationary on battery and only started the motor when the extra grunt was required?

 

It's fairly common knowledge nowadays that idling a car from cold to optimum temperature does more damage to the engine.

Idling should be no more than 30 seconds, then it needs to be driven off as the oil has circulated around essential components in that time and will then warm up much quicker than being idled. 

Most automotive oils are synthetic and show resistance to thickening at even -40 degrees and the viscosity of oil in Lexus vehicles is usually 0W-20

Warming up a car is outdated and not recommended. It's even written in the manual. It goes back to an age when cars had carburettors.

[Lost it]

Common knowledge or conjecture? Find me the engineering studies done by people with letters after their name that agree. Motor engineers who work for car manufacturers don't count. And explain to me why the aircraft industry in particular demands that engines are warmed thoroughly before any kind of take off is attempted. Because according to you it's possible to start the old Lycoming or some such piston engined helicopter from freezing cold and take off immediately. (And no doubt fall out of the sky soon after). I think the armed forces demand this too. Do they know less than vehicle manufacturers trying to "game" the fuel consumption figures?

Am I too cynical?

Or do you think it's simply because it doesn't matter if an engine fails on a car?

 

[rayaans]

9 minutes ago, Lost it said:

Common knowledge or conjecture? Find me the engineering studies done by people with letters after their name that agree. Motor engineers who work for car manufacturers don't count. And explain to me why the aircraft industry in particular demands that engines are warmed thoroughly before any kind of take off is attempted. Because according to you it's possible to start the old Lycoming or some such piston engined helicopter from freezing cold and take off immediately. (And no doubt fall out of the sky soon after). I think the armed forces demand this too. Do they know less than vehicle manufacturers trying to "game" the fuel consumption figures?

Am I too cynical?

Or do you think it's simply because it doesn't matter if an engine fails on a car?

 

Last time I checked, light aircrafts used oil derived from mineral oil which is natural oil and to top it off have much higher viscosity. They don't use fully synthetic oils. Mineral oils start getting thick below zero. Fully synthetic oils don't. 

Any decent mechanic will tell you that a modern car doesn't have to be warmed more than 30 seconds. Cars nowadays even have rev limiters which go up the warmer the car gets nowadays

[Zotto]

The oil topic for hybrid cars is a bit more complicate. At starting, there is a warming phase (eve if you decide to move in EV mode), in which thermal engine has to reach  40° C idling, once this temperature has been reached engine goes off, ready to restart if needed asking more power than the available by electric motor, if Battery needs charging or if speed is over minimum speed in which it has to be anyway on. Besides, in  hybrid cars thermal engine, in slow speed situation or when v diminish, is off or working without burning fuel (like in usual cars speeding down), so the result is an average working temperature lower: in this situation, the importance to have a proper oil is quite important, even more in starting time, and for this reason hybrid use  0W-20 oil, not only to spare fuel being it more "fluid". Last engines (like that in UX) require 0W-17 oil.

This is also the reason why Lexus and Toyota ask to change oil more often than other car brands, than can use thicker oils and "long life", or in sport cars (where fuel consumption is not a priority and working temperature is high) it' s better to use 5W-50 or more.

[Lost it]

On 7/21/2019 at 10:05 AM, rayaans said:

Last time I checked, light aircrafts used oil derived from mineral oil which is natural oil and to top it off have much higher viscosity. They don't use fully synthetic oils. Mineral oils start getting thick below zero. Fully synthetic oils don't. 

Any decent mechanic will tell you that a modern car doesn't have to be warmed more than 30 seconds. Cars nowadays even have rev limiters which go up the warmer the car gets nowadays

Again. Light aircraft piston engines don't use Synthetics because they usually run Leaded fuel as well to prevent knock at altitude when the motor's by definition run weaker and synthetic polymers don't work too well with leaded petrol wash down. (Historical foot note, early WW2 pictures of Spitfires and Hurricanes were doctored before being published to hide the white staining of the engine panels caused by the lead content that helped them make the power they did).

Post 3...

http://www.sonerai.net/smf/index.php?topic=2341.0

Still recommends warming the engine before using it. Usually a single grade as well.

Mechanics frankly are not Engineers and will tell you what the manufacturers want you to hear becausre that's the guidance they have.

Engineers have letters after their name. And the term usually means they design and build the stuff. And I'm a member of a few "clans", get all kinds of publications and nowhere have I seen a recomendation to drive off a stone cold engine within 30 seconds of start up. It's the manufacturers gaming the fuel consumption figures to get cars into different tax bands, or make their vehicle mpg figures look better. These same manufacturers don't really care what damage you do to your engine as long as it lasts past the warranty period.

My 2007 Honda VFR Vtec won't let the Vtec work until the engine reaches 60C. All Vtec is on these vehicles is an actuating plunger that slides across under oil pressure to activate 8 more valves after a certain RPM threshold is reached. So even Honda know that cold oil isn't good for engines. So if there are cars changing rev limits according to engine heat, what does that tell you about whether the engine should be warm or not? Kind of contradicts itself?

It's ok to start it and drive it off immediately but you can't actually use all the performance until it warms up?

That is an oxymoron if I ever saw one.

[croxster]

Sorry but an engine doesn't need to warm up just get in and go it won't do any harm I work for a standby genset manufacturer the customers of these engines don't want to sit and idle there engines they want power and they want it now!!!!! I think the standered is from initial start up to full load in around 15 seconds and it can stay there for days on end
The tolerances of modern engines and millions of pounds of development it takes to put an engine into the public hands they can cope with a lot more than you think.

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[Lost it]

1 hour ago, croxster said:

Sorry but an engine doesn't need to warm up just get in and go it won't do any harm I work for a standby genset manufacturer the customers of these engines don't want to sit and idle there engines they want power and they want it now!!!!! I think the standered is from initial start up to full load in around 15 seconds and it can stay there for days on end
The tolerances of modern engines and millions of pounds of development it takes to put an engine into the public hands they can cope with a lot more than you think.

Sent from my SM-G935F using Tapatalk
 

Erm.. Every Stand bye Genset I've ever worked on is a Constant Speed Unit. Usually turbo charged and has ALWAYS had a water jacket heater turned on 24/7 as well as Battery chargers turned on if they are near to a mains supply. One was a Hospital, one was a computer "farm" and one was somewhere else. Different horses, different courses. They also usually run on Gas oil.

 

What I'm talking about is an engine with a rubber band driving four camshafts, with a variable valve system that runs on oil, that produces circa 200bhp from less than 3 litres, in a V formation so it's a long way to the top of the engine from the pressure relief valve and the flow has to be split between two banks of cylinders to lube those cams, from a pump that is fed by the crankshaft turning (2-300rpm at starting?) which then feeds an oil filter, and is either filtered or bypasses the filter. So there's a rea;l risk that not much oil at all is going to be reaching the parts it needs to reach.

To start this engine up from cold, in winter, and drive it off immediately is never ever going to do it any good. That's what I'm saying and no vehicle manufacturer who is gaming fuel consumption figures will ever change my mind. Sorry.

There isn't yet any engine, bearing surface either camshaft or crank that can run without some kind of oil film. And as good as modern oils are, they have to be pumped. Unless the cam itself sits in a bucket of oil like the old Vauhall Victor OHC engine used to do, there's just too much risk of scuffing damage to bearing surfaces, rockers, cam geras, even the oil pump itself..

Think on most engine warning lamps are fed by the ECU now, not directly.

[croxster]

Yes and what I am also saying is in years and alot of money spent on development these engines are tested well in the extremes that the engine is likely to ever see and more so like testing in sub zero temperatures and generally thrashed to breaking point

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