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Is The Is Safe In Heavy Rain?


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Thank you Steve, I do find this forum very defensive, interestingly none of the posters saying 70 is too fast drive IS's, if I was retired driving an old Lexus for pleasure, I would probably slow down, but my car is used to earn me a living so I have to drive between appointments, and I will slow down if necessary, but if I have a 200 mile journey to make I will not slow to 55-60 (unless it is snow!)

Like you I use Rainex, if I can drive in Rain without wipers, and still have a clear view, I do not deem it too heavy!

Your comments re-assure me, and will investigate the tyres further tonight if I get a chance, as I suspect something may be slightly out there, as 70mph in a modern car should be safe.

Using Rain X gives you a false sense of security as it makes the glass seem clear whereas the conditions are totally opposite. The thunderstorm last Saturday on the M1 was atrocious, I had my window sealant on and could see everything yet, I still slowed down. Visibility may not be an issue but tyres can't see, they can only adhere to the surface and rely on the driver to adapt to the conditions. Now if you removed that sealant and drove in the same conditions, you'd understand exactly how heavy the rain was.

70mph in a modern car is safe in the dry - heck I go at 100mph in my RX with one hand on the steering wheel. But if its wet, you aren't going to stop anywhere near as quick as you would in the dry and that makes all the difference so you need to reduce your speed.

It doesn't matter if you're David Cameron or John Smith, heavy rain means reduce your speed. If you're having traction issues, it definitely means you need to slow down.

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My impressions of driving the 300h in wet conditions are more than favourable, by which I mean that I recall no

occasions when the car has behaved unpredictably in situations varying from slipperiness caused by oily drizzle

to voluminous surface water, flowing and/or standing, caused by violent downpours. The feeling of helplessness

and momentary loss of control and/or lateral wobble inevitably experienced upon aquaplaning at approx. 70mph

=110kmh (which is today the motorway limit in the wet in much of Europe) on OEM 18" Bridgestone Turanzas is

no different from that you get with less fat tyres, and, as long as the road is fairly clear of other vehicles, especially

heavy ones that kick up a lot of spray, and there are no gusting side-winds, I personally judge this to be an

acceptably safe speed even in heavy rain. This is really another way of saying that, in terms of safety margins

in poor driving conditions, I tend to worry less about myself in the 300h than about other people in other cars.

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In 'difficult' driving condition 'less' is very often so much 'more'. I'm relating to tyre width here. A narrow tyre will more often get you through the mud, snow and surface water simply because its thinner section will cut through the surface easier than a wider tyre that sits 'on top' of the surface. One only needs to look at rally car tyres to see an example of this. OK so we generally don't need studs or M+S rubber, but the Europeans perhaps have the best answer with summer and winter sets of tyres.

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Not really noticed issues in heavy rain, but the last time I drove it on motorway in high wind it scared the living daylights out of me! Drifted hugely across lanes totally unexpectedally - and before someone says I was driving inappropriately, This is my third, and probable last, Lexus IS, and never had this terrifying experience before! I'd put it down to bad design and lack of wind tunnel testing!

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Not really noticed issues in heavy rain, but the last time I drove it on motorway in high wind it scared the living daylights out of me! Drifted hugely across lanes totally unexpectedally - and before someone says I was driving inappropriately, This is my third, and probable last, Lexus IS, and never had this terrifying experience before! I'd put it down to bad design and lack of wind tunnel testing!

Worth noting that every Lexus is tested in a wind tunnel to help with reducing wind noise. Lexus have their own facility which they showed off in an RCF video.

Never had an issue in high wind with the IS. The IS has a brilliant chassis and is very stable at speed so frankly, I don't believe you. Sure you're alignment wasn't off?

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No comment on the suitability of the IS in bad weather, but I definitely did not enjoy being on the western stretch of the M25 at around 2pm today. It was orrible, with a capital O. Why oh why can't they fit some sort of spray retainer on HGV wheels?

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I must have posted this several times now...

http://www.caranddriver.com/comparisons/2014-lexus-is350-f-sport-page-4

The IS350, which we don't get here in the UK, has essentially the same chassis as the IS300H. In test after test its been judged by 'motoring experts' as to been on par / better than the latest F30 BMW 335i. Which is by all accounts the gold standard of small saloons, excluding the M/RS/AMG cars.

Speaking from personal experience of owning a E90 335i modified to 380bhp for nearly 4 years, and now our IS300H for 6 months, the chassis on the IS300H is leagues better than my old 335i. It rides better, the stock suspension damping is much better, and there is plenty of 'feel' through the buttocks/steering wheel about what the car is going to do. You can carry a huge amount of speed through twisty corners, and almost regardless of how poor the road surface is the car will stick to the line you want. That kind of road holding inspire confidence, and in my book are hall marks of a good car. If Lexus offered the IS350 or hinted at developing a IS-F based on the current chassis I would be very tempted - despite my obsession with EV drivetrains.

Frankly I'm amazed anyone can suggest the IS300H is 'unsafe' in rain or high winds. Personally I cannot wait for some snow to hit the ground so that I can see just how 'playful' the chassis can be :)

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I'd give the OP or anyone that suffers this sort of issue a break - each car is different - tyre pressures, binding brakes, speed, overtaking high sided vehicles, premature ageing of compound, alignment, road surface quality/camber, etc can all cause these issues. Then add aquaplaning on wide wheels and you have potential.

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  • 4 months later...

Recently I have noticed the car seeming to tramline badly, which could could be related to my previous issues, I had the tracking checked, but it was within spec, however when the garage checked their data base it showed the pressures should have been 46/4 psi, they inflated to this as a trial and it seemed to run true, anyone use these pressures, they seem excessive, and make the ride even worse.

The car had now done 21k, and I changed the rear tyres to uniroyal rainsport 3's a few weeks ago, which improved the ride and noise levels over the bridgestones, the front tyres still have 5.5-6 mm but the tram lining was there before hand, is it a characteristic of the hard bridgestones once they are half worn?

At the moment the car is not pleasurable to drive, I need to get these issues sorted.

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46psi is daft, the car should be running on 36psi all around.

Id check the torque of the wheel nuts for a start should be 76 pound feet. Most likely its the tyres that are causing the problem.

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I agree 46/49 psi seems ridiculous, but thought it worth a try.

After a bit more research, I have found common causes of tramlining are:

"high performance tyres" are more likely to tramline than those with deeper treads, as they have more contact with the road, and so tend to be more influenced

Long wheelbase cars tend to be more sensitive

Runflat tyres due to stiffer side walls transmit more road faults, hence making the tramlining worse.

Although the Bridgestone ER33's are not runflats, the sidewalls are incredibly stiff, the first point would make sense as the problem is getting worse as the tyres wear down.

Looking back, I think tramlining has been the problem all the time, a lot of the roads I drive on (A12 particularly) are worn out tarmac, which have deep ruts caused by hgv's these are the roads where the car tends to "wander" as it moves in and out of the ruts.

Looking on various forums Bridgestone's do tend to be susceptible to tramlining. so I may decide to junk the bridgestones with 5-6mm left in favour of the uniroyals which despite just being on the rear have already improved the noise levels in the car.

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You need to get a four wheel alignment check done(not just tracking) on the car as the first action. Only this will tell you if there is something wrong with the the wheel setup, or god forbid the chassis of the car.

Anything else will just be guessing.

It could be that the toe or castor is out of spec, suspect camber wouldn't cause tramlining.

Admittedly those tyre pressures seem way too high, but if you had them set lower previously and still experienced tramlining then the issue is still there regardless of pressures. I also used to drive the A12 from Witham to Brentwood daily and never experienced bad tramlining.

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Can't really say I have any concerns about safety in heavy rain (compared with dry roads) - but a couple of weeks ago I had to have both rear tyres replaced owing to severe wear on the inside edges of both rear tyres. This wear (pointed out to me at a service) was so severe that the inner two inches of tread was completely worn away and the metal re-inforcement was clearly visible - ready, I guess for a blow-out. I totally missed seeing this as the outer edge of the tyre was well within legal limits. I had a front tyre renewed about 8000 miles ago when it took a nail in the side wall. Car is on contract hire and company only authorise Michelin. So I had the two rear tyres replaced and 4 corner tracking done etc. The very first thing I noticed was that the Michelin tyres run a little quieter than the OEM Bridgestones. They didn't really make too much difference to its tendency to 'track' on poor road surfaces or 'tramlines' left by HGV's. Can't really say that the 'tramlining' is dangerous - irritating perhaps. My experience over the years driving cars with low profile tyres is that once they wear down a millimeter or two from the legal minimum tyre depth they WILL tend to tramline. In my case the fact that I had two new rear tyres fitted and with one 8000 mile tyre and an original tyre on the front end it explains (to me anyway) why the car will still 'tramline'.

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Speed itself Never Kills. One can drive 200 mph on an empty track without traffic in great weather. It is always speed in combination with something else that creates danger. rain, fog, dense traffic, lorries and so on. I dont think it is possible to judge the situation only be 70mph rain and aquaplaning as we dont know about road surface, tyre wear, wind, puddles etc. However, if you run into problems at 50,60,70 or 100mph then clearly something needs to be adressed. Driver mindset could be the first and easy thing to do, lift off reduce speed on that part of the road. Then Check The Car. tyres, balance. The F-sport has some pretty wide and flat tyres and this by definition is more prone to aquaplaning than skinny tyres. A friend of mine wrecked his 911 in pooring rain doing less than 50mph on the highway when his car started driving on water simply spun around and went into the armco backwards, nothing he could do!

Drive Carefully! ( and that does not mean drive slow..)

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Can't really say I have any concerns about safety in heavy rain (compared with dry roads) - but a couple of weeks ago I had to have both rear tyres replaced owing to severe wear on the inside edges of both rear tyres. This wear (pointed out to me at a service) was so severe that the inner two inches of tread was completely worn away and the metal re-inforcement was clearly visible - ready, I guess for a blow-out. I totally missed seeing this as the outer edge of the tyre was well within legal limits. I had a front tyre renewed about 8000 miles ago when it took a nail in the side wall. Car is on contract hire and company only authorise Michelin. So I had the two rear tyres replaced and 4 corner tracking done etc. The very first thing I noticed was that the Michelin tyres run a little quieter than the OEM Bridgestones. They didn't really make too much difference to its tendency to 'track' on poor road surfaces or 'tramlines' left by HGV's. Can't really say that the 'tramlining' is dangerous - irritating perhaps. My experience over the years driving cars with low profile tyres is that once they wear down a millimeter or two from the legal minimum tyre depth they WILL tend to tramline. In my case the fact that I had two new rear tyres fitted and with one 8000 mile tyre and an original tyre on the front end it explains (to me anyway) why the car will still 'tramline'.

All IS F-Sports of this generation will have issues with inner tyre wear on rear tyres looking at the camber. No adjustable camber from what I can see either.

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Speed itself Never Kills.....

Drive Carefully! ( and that does not mean drive slow..)

Sorry but that's just utter RUBBISH!!

Ofcourse speed kills, kinetic energy squares with speed. If you crash as 100 mph per hour your basically dead, where as at 50 mph you have half a chance.

I enjoy a bit of speed as much as anyone else but I'm not stupid enough to believe that speeding isn't dangerous.

Why do you think people auqapalne?? The faster you drive the more chance of aquaplaning, the less reaction time you have, and more chance your die, or worse kill some one else.

Next your be arguing that F1 cars generate more grip the faster they go around a corner, therefore road cars should be allowed to do the same.....But just remember F1 car generates aero grip, where as road cars generate lift ;)

With attitude like yours I cannot wait till legislation comes along that forces automated driving on M-ways, or at the very least limit the speed. If you want to speed go to a track.

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Gang, if you had read Dutchies post correctly you would see that he didn't say speed does not kill. He said that speed itself never kills. He actually was correct when he posted.

" It is always speed in combination with something else that creates danger. rain, fog, dense traffic, lorries and so on".

Drive within your capabilities and the capability of the car and hope others do the same. People get killed in collisions even at low speed.

As for tramlining in the tracks left by HGV s over the years, I have found that the wider the tyres on your car the more this occurs.

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Like Ross (see #42 above), I confirm there is a problem of wear to the rear tyres. Since I had never pressed my head

to the ground in order to look, the wear was only discovered when I changed to winter tyres. Alarmingly, the metal was

visible on parts of the inside treads of both the OEM Bridgestone Turanzas (255/35/18), which had then done 33,000km

(=20,5K miles). Because the front ones were still looking good with a remaining tread of 6mm, I had been expecting to

do at least another 5,000km. The winters (Yokohama W.Drives 245/45/18) had done 18,000km (=11K miles) and all

four were still looking good and evenly worn with plenty of meat left on them. They have now reached 22,500km (=14K

miles), and I will almost certainly get one more winter out of them.

What especially disturbed me when I was shown the extent of the wear to the Bridgestones is that I had not felt any

decline to the car's road-holding and performance. This presumably means that I am either not a sensitive driver or

that I place too much reliance on the 300h's driveability - which could also mean that the car has lulled me into a

state of false security. According to the Lexus mechanics, relatively quick wear to the 300h's rear tyres of whatever

brand is not unusual, though they had not previously seen any as bad as mine.

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On 19-1-2016 at 6:09 AM, ganzoom said:

Sorry but that's just utter RUBBISH!!

Ofcourse speed kills, kinetic energy squares with speed. If you crash as 100 mph per hour your basically dead, where as at 50 mph you have half a chance.

I enjoy a bit of speed as much as anyone else but I'm not stupid enough to believe that speeding isn't dangerous.

Why do you think people auqapalne?? The faster you drive the more chance of aquaplaning, the less reaction time you have, and more chance your die, or worse kill some one else.

Next your be arguing that F1 cars generate more grip the faster they go around a corner, therefore road cars should be allowed to do the same.....But just remember F1 car generates aero grip, where as road cars generate lift ;)

With attitude like yours I cannot wait till legislation comes along that forces automated driving on M-ways, or at the very least limit the speed. If you want to speed go to a track.

Wow Ganzoom, what a great rant, i realize that reading can be difficult for some of us but it seems you are replying to a different post altogether?  

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Moving on :whistling:... now about RainX... tell us more...  I have started a thread on the RX forum asking about hydrophobic products...

Do you spray it or put it in the tank?

More importantly do you recommend it?

(I take note of Ryaan's comment that front side windows already have a water repellent coating (RX only or all Lexus models, I am not sure)

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