Performance of IS300H

[RichyRich]

Is the 300H limited to 125mph? Ever since I got in the car and drove it away from the Lexus dealer 2 months ago I feel the need to put it in Sport on occasion and put it through it's paces on a clear stretch of road. Only issue I have is I run out of road or traffic means I ease right off and not quite get to see what she can do.

Feel sort of naughty for asking what other 300H owners have got it to. Does the F-Sport engine sound make you want to drive a bit more like a 21 year old just passed their test?

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[rayaans]

Yea limited to 124mph. I've done stupid speeds before and it was stable I. E one handed effort. 

I've never ragged it though, it's always pretty smooth acceleration and braking 

[RichyRich]

Must go beyond 124 surely.

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[NemesisUK]

Why? The RC300h is electronically limited to 119 for economy reasons. 

[RichyRich]

23 minutes ago, NemesisUK said:

Why? The RC300h is electronically limited to 119 for economy reasons. 

 

Gone are the days of 150mph I guess for our own safety I suppose 

[rayaans]

Its not to do with economy.

Its because the hybrid components can't handle more than 124mph. The exception being the GS450h which can go to 150mph.

The IS200t goes to 143mph so its not the components of the rest of the car

[NemesisUK]

Interesting, in what way can't the hybrid components cope with higher speeds? 

[ganzoom]

48 minutes ago, NemesisUK said:

Interesting, in what way can't the hybrid components cope with higher speeds? 

 

The Lexus hybrid system is essentially a modified version of the drive train from a Prius. It was designed from the onset to favour economy over performance, I suspect motor/battery temperature at high speeds are physical limits of the system. Try touching the boot area on the IS300H after a M-way run, it's fairly warm due to demands on the Battery. The IS300H's power train is at its best been driven at 5/10th, ie at a leisurely pace. A 'sports' car it most definitely is not. 

[RichyRich]

Interesting info guys. The RC300h isn't it the same engine and hybrid? 119mph!!

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[royoftherovers]

13 hours ago, RichyRich said:

Must go beyond 124 surely.

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Why would anyone wish to drive at speeds beyond, or at 124 mph? A jet liner takes off at approx 150mph.

 

 

Regards

John

[RichyRich]

On the Autobahn

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[Zotto]

The Hybrid eCVT system has 2 electric engines that have to reach high revs speed, and this is the reason of limitation, to not exeed 11000 rpm on electric engine.

GS 450 h  have 2 different gear ratios to bypass this limitation.

 

[RichyRich]

450H next then ☺️

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[ganzoom]

1 hour ago, RichyRich said:

On the Autobahn

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Your struggle to get anything without 300bhp+ to 150mph on the Autobahn. You need a long stretch and a car that call pull hard well past 130mph, most cars under 300bhp will nearly stop accelerating past 120mph and than crawl up to their vmax. 

[OldTrout]

If 

 

is to be believed the 450h gets to 100mph in about 12 seconds and 150 in 24. I wonder if the 450h could be back to zero before the BMW hits 260kph?

[royoftherovers]

3 hours ago, RichyRich said:

On the Autobahn

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Been on the Autobanh Richy four times in my GS450H.

If you like driving at those speeds for any length of time, then you are probably in the wrong job..

Autobahn crashes at those speeds are usually fatal for all those involved.

 

Regards

John

[RichyRich]

Not likely to get near the Autobahn tbh. I was just speculating the performance capability of the Hybrid. Most of my time is spent doing short commutes and the school run 😂

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[BigChange]

Was interested in Ganzoom's comment viz "Try touching the boot area on the IS300H after a M-way run, it's fairly warm".  

Does this mean I should be careful what I pack in the boot for the long run home from France (on fast peages) laden with cheese, wine and other delicacies?   Not had the car very long but can't say I have noticed any warmth in the boot after a long run. 

 

[Platypus]

Mine is in kph. The speedo on the IS300h always shows 10% faster than you're actually driving (for whatever reason I don't know). I checked with a Coyote and at exactly 200km/h (around 220 on the clock) she stopped accelerating.

 

 

[rayaans]

6 hours ago, Platypus said:

Mine is in kph. The speedo on the IS300h always shows 10% faster than you're actually driving (for whatever reason I don't know). I checked with a Coyote and at exactly 200km/h (around 220 on the clock) she stopped accelerating.

 

 

Its a built in safety net in all cars. 

VW has 10% as well, with speedo showing 80mph and the GPS on tomtom showing about 72mph. 

[Rabbers]

21 hours ago, Platypus said:

...The speedo on the IS300h always shows 10% faster than you're actually driving...

10% seems high and could be a U.K.-specific setting.   Two Italian motoring magazines routinely measure Actual v. Speedo differences in

their new car reviews and, as regards the 300h, Quattroruote, October 2013, gave a deviation of 4.8% at 130kmh (which was surprisingly

high compared to 1.3% for the VW 2.0 TSI and 1.4% for the Audi A3 1.8 TFSI reviewed in the same issue).   Panorama Auto, August 2013,

recorded actuals of 47kmh at 50kmh, 88kmh at 90kmh, and 127kmh at 130kmh, namely deviations of 6.0%, 2.2% and 2.3%.  These were

largely similar to the figures for other cars reviewed in the same issue, e.g. VW Beetle TSI, Chevrolet Malibu, Renault Captur, though the

300h was closer to actual at higher speeds than any of them.

 

Personally, as a rule of thumb, I keep 5% in mind regardless of the speed, this being what experience in several countries tells me to be,

give or take, a fairly customary difference between my speedometer readings and the figures shown on courtesy speed monitors in the

expectation that the latter are accurate (which, really, I trust them to be only in Switzerland).

 

 

[Platypus]

I stand corrected! Indeed, 10% is a bit on the high side; it's more like 7-8% at 120kph but seems to be on a sliding scale with higher discrepancies at lower speeds. Not a UK car, I'm in Belgium. Compared it to my Coyote which gives the same speed as my Garmin. Used the same gear in an Opel Corsa and it was within 3%, just like my old Saab 93. Thought it might be a Japanese safety thing it inherited because my wife's Toyota Auris is also around the same tolerances. 

Can't trust their advertised CO2 figures, so don't trust the speedo either! :))

[Rabbers]

Of course the 300h is not a sportscar.  Beyond its satisfactorily lively day-to-day performance on normal roads it is, however, perfectly

suited to long-distance driving at cruising speeds that are as high as you are ever likely to require given even the most liberal national

speed limits you will find anywhere today.  I drive the length of Germany several times a year, entirely on the autobahn network, and 

have no trouble cruising relaxedly at 150-160kmh (=93-100mph) and, if the traffic is sufficiently light and I am inclined to do so, which

is rarely, I can easily increase this to 180kmh (=112mph) without straining the 300h.  Once or twice, on a downhill stretch on which I

look forward to driving, I have seen the speedometer touch 210kmh (=130mph) without apparent effort, and while I was aware of the

speed my passenger was not.  Of course the actual speed was lower, probably by 5% or so, meaning that the declared limitation to

200kmh(=125mph) is accurate enough.  In practical terms, long-distance autobahn driving in the 300h putting your foot down whenever

you can while broadly observing the speed limits wherever these are present (which is increasingly frequently and which the police

and most of the population take seriously) means that the approx.1000km between the Swiss and Danish borders can usually not be

done in under 10 hours, the main obstacle to a higher average speed being extensive and extremely irritating roadworks which can bring

you to a complete stop at regular intervals over the entire route.   While I wouldn't claim to feel as fresh as a daisy at the end of this kind

of drive, it nevertheless always impresses me how nicely the car has performed.

[Rabbers]

On 9/23/2016 at 8:55 PM, BigChange said:

Does this mean I should be careful what I pack in the boot for the long run home from France (on fast peages) laden with cheese, wine and other delicacies? ....

I don't suppose that many 300h owners worry too much about gastronomic delights perishing in their boot but I must admit that I am one 

of them.  I too was concerned about potential heat from the batteries, especially when I first saw the cooling vents inside the rear door-frames.

Like BigChange, I carry foods and wines in the boot on long motorway drives, usually at the request of relatives and friends at destination (or

for personal consumption on long stays).  For security's sake and as a matter of aesthetic principle, I never put bags or parcels on the back

seats on long journeys even when the contents would benefit from the aircon.  My stubbornness in this regard as often as not LED me to curse

the boots of past IS generations, particularly the 250, which had areas of quite intense heat generated by the brakes and axle, the oven effect

being compounded from above in hot summer sunshine.  To my relief, I found the boot of the 300h to be significantly better not only because

the batteries appear to be well insulated - in my experience they can be warm after long drives but not alarmingly so - but mainly because its

greater depth means that anything loaded towards the back is tolerably well insulated from the sun by the rear cabin shelf above.  Nevertheless

I invested several years ago in a set of heavy-duty thermal bags, settling, after being disappointed with various other cheaper products, for a

German brand called BECool, which has never let me down.

[Zotto]

Be happy, HV batteries in hybrids are well monitored in temperature, and there is a ventilation system to keep them relatively cool.