Is300 Top Speed

[ChrisIS200SportTTE]

Since owning the 300 I've joined a few American IS300 owners pages on Facebook and a couple of US IS300 forums as there's much more information on the 300 across the pond as they sold so many more there.

The one thing that keeps coming up is the top speed of a stock IS300. I believe this to be about 140-145mph. I've done a top speed run in mine (private road of course) and got it showing just over 140mph. Taking into consideration the speedo over reading, I'm guessing I'm doing 135mph ish.

Now nearly every single American I've spoke to swears that their car will do 150mph+.... Some even claiming 160mph stock!!

I really don't believe this.. I mean, it's the same car right? The Americans didn't get a quicker 300 did they?

[The Transporter]

I do believe that the US got manual IS300s.....But there is one guy here who will be able to say exactly how fast he thinks his IS300 is

Alway take what a Septic says with a pinch of salt......

[IHgs300]

I would have thought it should be higher than that Chris? The 99 GS is limited to 240km/h (149mph). Same engine as yours but the GS is heavier.

[LexIS200Sport]

Are the gearing and final drive ratios between the GB and US IS300 autos the same?

[petayV8]

Yeah a manual will be faster plus some is300s over there didnt have half the options such as heated seats and others but saying that cant see it making a huge difference. It does aeem quite low for me i must say cus wont a is200 do about 130?

[ChrisIS200SportTTE]

Well they say there's no difference between the manual and auto in terms of top speed (the Americans that is)

Official top speed of an IS300 is 145mph that I can find online anyway.

I think a lot of these guys are exaggerating a little. I know for a fact my IS300 will not do 150mph! And it's just had new plugs, oil, air filter etc

[ChrisIS200SportTTE]

Are the gearing and final drive ratios between the GB and US IS300 autos the same?

Yes, as far as I can determine it's exactly the same car with the exception of the steering wheel on the wrong side

[petayV8]

hmm dont really see why they would feel the need to exaggerate tbh. the IS300 isnt fast or powerful by american standards (or even my standards) and a 3.0L car is the norm over there.... in fact i heard one american review complaining how slow it is lol which while were on the subject, i dont class it as a fast car at all, and find it funny that ppl do. i guess on UK road where probably 50% of cars have less than 100bhp or around it can be justified but as it stands..... and im sure you'd agree Chris if i recall your car history - youve had some beasts

[noby76]

haven't had mine at 150 + mph but have had it around 145-147mph this was against a Type R Honda from around 3rd gear in gear acceleration pull and those cars a very quick.. put it this way. the Type R is officially down as 146mph and if you work out their power to weight ratio this is the same as a GS430 V8. and we went all they way to 145-147mph and both backed out this was on a closed road of course. at that speed my RPM was at around 5500rpm so there was more rpm left for the engine to play with .. the 4th gear of IS300 tops out at 130mph on the speedo which in reality is around 125mph road speed as confirmed a GS300 with the same drive train and engine as IS300 and heavier can do 150mph smoothly. have a look on youtube.. is not a fast car without the Turbo strapped to it but has performance and handling most will need for day to day driving if one is not a horsepower freak.

thing is, not all manufactures give the real performance figures of their cars some either tone it down for insurance purposes. or state figures which matches that of their competitors models.

this is a 3.0 Legacy Subaru which might be my next car due to better mpg, space and awd compared to my IS and in sport mode, this thing tops 240kph(150mph) in 4th gear alone. at 5th the driver was only cruising at 5000rpm so will 5th take it to 160mph+ if road permits? .. Subaru has stated top speed on paper as only 143mph this is the same as IS300.

http://www.youtube.com/watch?v=b9NaQz9R6AA

[TigerFish]

Speedo inaccuracies tend to be around 10% (it probably gets even worse the faster you go), therefore 160 would be roughly 144, close enough to 143 for most folk. Given head winds, tail winds, inclines, declines, tyre pressures, road surface, factory optional extras, after market wheels and unsprung weight, etc, etc, all these variables can give a tad more or a lot less top speed.

[noby76]

quote from this link

The UK law is based on the EU standard, with some minor changes. A speedo must never show less than the actual speed, and must never show more than 110% of actual speed + 6.25mph. So if your true speed is 40mph, your speedo could legally be reading up to 50.25mph but never less than 40mph. Or to put it another way, if your speedo is reading 50mph, you won’t be doing more than 50mph but it’s possible you might actually only be travelling at 40mph.

http://www.thecarexpert.co.uk/how-accurate-is-a-car-speedometer/

thing is we all don't go by real road speed when we hop in our cars. we all go by the speedo on the guage of our cars.

[ChrisIS200SportTTE]

hmm dont really see why they would feel the need to exaggerate tbh. the IS300 isnt fast or powerful by american standards (or even my standards) and a 3.0L car is the norm over there.... in fact i heard one american review complaining how slow it is lol which while were on the subject, i dont class it as a fast car at all, and find it funny that ppl do. i guess on UK road where probably 50% of cars have less than 100bhp or around it can be justified but as it stands..... and im sure you'd agree Chris if i recall your car history - youve had some beasts

The reason people exaggerate Pete is because it makes them feel better and they think they are impressing others lol...

I totally agree, the 300 isn't a fast car. Faster than the 200 yes and probably fast by general UK standards but it's nothing compared to my old 300zx twin turbo

I also find it quite sluggish even with the Ect power thingy on (to be honest all I can see that do is turn on a nice little green light on my dash)

[noby76]

300ZX were making around 280 - 330 bhp Chris so that car was way above UK standards lol.. but as you say by UK standards and what you normally see on roads the 300 is fast in ECT PWR M mode so it wont be an exaggeration. I personally regard anything which does 145 -150mph on the speedo fast as that's all one needs to experience to know they are travelling fast.. anything above that and one will need a lot and I mean a lot of concentration and dare I say experience to keep the car planted and control. anything over 155mph is very deadly hence most manufactures limit their cars to 155mph as anything above that is asking for trouble.

there is a difference between 'quick' and 'fast' the 300 is not quick to 60mph but fast from 60 to 150mph on the speedo that's all one needs to experience to know they have a fast car.. nothing more :winky:

[ChrisIS200SportTTE]

Yeah granted the 300zx was a bit special, Japanese import and it was so so quick! I don't ever remember being out accelerated in that car

I got out accelerated by a Renault Megane Sport yesterday, that disappointed me.

The IS300 just feels a bit big and clumsy which is strange as I know it's the same shell as my old 200 but to me it honestly feels like a much bigger car. I think I was expecting the acceleration to be a little better that's all.

And yeah most of the American lads on the forums etc say the 300 is a slow car in stock form and by their standards they're right.

[steve2006]

I find using a sat nav more accurate than the speedometer.

I find that when going through motorway roadworks with a 50MPH limit at 50 on the speedo I am actually doing 47.

[The Transporter]

I too use a cheap eBay satnav as a speedo on my Jeep as the tyre and axle mods make the speedo a mile out....

[matt-c]

thing is, not all manufactures give the real performance figures of their cars some either tone it down for insurance purposes. or state figures which matches that of their competitors models.

No

[noby76]

care to highlight further on your blant response??

I wont result in going on a debate with you for the sake of saving Chris's thread mat but what you need to know is not all car models which come out of the factory are the same. manufactures tend to tone down or go by average figures and not the highest number they can find i.e. they might test 0-60mph and top speed of a few number of cars on the dyno using the same model and pick the average performance figure which is most consistent during the test. others might have two different models which perform very close against each other on 0-60 mph and top speed shoot out but in order to charge a little bit more for say model A, model B's figures will be toned down slightly on paper. e.g. IS250 vs GS300

a 2006 IS250 is down on paper at around 8 secs to 60 and tops out at 140mph..but numerous tests carried out buy car mag journalists rate it at 7 secs which matches the bigger GS300 and I proved 250's are capable of 160mph on the speedo in another thread a while back with a vid as evidence .. now if we minus 6 -10 mph from this figure as per the quote from car expert link I posted on page 1 regarding speedo inaccuracies , this still equates to 150 - 154 mph real road speed for the IS250. now don't you think Lexus might just tone the 250's performance figures down a lil bit to make the GS300 appear more superior on paper to those buyers and then command a higher price tag? if an insurance company knows your car is capable of 150 mph + its then classed as a performance/ high risk car which commands a higher premium as a result this is without factoring in ones no claims discount of course. you don't believe me? enter your details into money super market using IS-F as your vehicle and select 0 years no claims and let me know what you get quoted. once you done enter the same details using IS250 as your given vehicle and let me know the quote now do you think they might quote you the same premium if the 250 is capable of 150mph+?.. you saw a vid of a stock 3.0 Subaru Legacy topping 150mph on the speedo in 4th will it have accelerated to around 165mph from 5000 to a redline 7000rpm in 5th if the driver kept his foot in? your guess was as good as mine. again factor in 6-10mph as speedo inaccuracy and that's still 155 -159mph real road speed. last I checked the legacies were down on paper as 145 -147mph tops.

fact that an IS300 owner in US tops 155mph on his odo does not mean my 300 can. as no two cars are the same from factory and things like engine, engine oil, gearbox health plays a part. same as tyre pressures and even tyre size and spec. goodness even the weather/ air temperature contributes.

Chris to answer your question.. the 300 does over 140 - 150mph and during my two year ownership I have only done this once and only for a few secs. does it feel good knowing your car is capable of this speeds? Yes..is this a speed you will subject the car to regularly? No.. ask the IS-F owners how often they have hit 170mph since they have had their cars and if they have,, ask how often..

[matt-c]

Do I care to go into detail? No.

However, if you think that manufacturers downplay their specs to "fall inline" with their competition, then you are stupider than you sound. First basic rule of retail commerce; have a product that is better specced than the competition.

And no, I didn't read the rest of your post past the first, brevity laden line.

Now be gone with you, foolish boy

[noby76]

oh so you didn't read all and decided to make such a stupid comment as you always do?? me a fool? maybe the intelligence might be a lil too much for you to handle.. I can understand if you are not used to it... don't come on here tryna take it on some one if Santa did not honour what you so expected for Christmas.

in the automotive industry, there is something called 'Gentlemens Agreement' and this is a set of rules car manufactures go by. now don't think different car manufacturing CEO's do not sometimes sit down behind closed doors to agree on a 'product' which in this case, a car and regardless of badge, they can agree all their 3 litre models within a price tag of say £30-£40K should not exceed say 260bhp must not do more than 152mph and should not hit 60 any lesser than 6.5secs .. this is to keep cost down for all of them, which prevents them from trying to out do each other in the market they targeted.. now can Toyota or Honda produce a 3 litre car which makes 300bhp, hit 60 in about 5 secs dead and top out 170mph? sure they can. they all have experience in F1 engineering and have huge budgets to produce any type of engine they wish.. they both have two litre engines which makes 200bhp which equates to 100bhp per litre so all they have to do is engineer same philosopy for a 3 litre but this will push costs up and in marketing, there is something called 'Target Market' and price dictates target market so in order to taylor a 3litre car for a £30k target market they all agree an whats known as the 'Gentlemens Agreemnet' because they know they will end up taking each other out of a specific target market and hiking up production costs which results in high cost of the vehicle if they don't 'fall Inline' with each other. but since you didn't bother reading you didn't not pick up on where I said not all two cars from factory are the same. after engine break in period one might be up 15 - 20bhp compared to another. and this can translate to 1 sec advantage to 60 and an extra 10mph top speed.

Now I hope you still don't wish to continue to make a fool of your self mat??

[The Transporter]

Still not got yourself a girlfriend then Knobby?

[dave1]

Where on earth did you pluck these "Gentlemen's Agreements" theories from? So Honda are happy to sell less of their cars in order to make sure that Toyota, Ford etc are not outdone and stay in business? Some of your previous posts have been equally as ridiculous and argumentative so do you deliberately post rubbish to incite argument to maybe "liven up threads"?

I notice you now have a Lexus is300.........did you sell your "4 door Supra"?

[noby76]

@Transporter

about time you tell the wife to do her duties by showing you some attention...I feel for you brother..

@Dave

re read my post again and quote where i said manufactures are happy to sell thier cars to keep others in business?? price dictates 'target market' market..a munfacturer can enginneer say an NA 3 litre car which can out do the other manufacturere by say 100 horsepower in order to achieve this they will need stronger engineering of parts which cost more money..this will result in them passing on that cost to the customer's buying price. now if the buying price is way beyond that specific 'target market' segment they have shot them selves in the foot by automatically taking themselves out of that specific market. e.g. Lexus releases a 2006 IS250 and then confirmes this will go 'against' BMW 325i, C250 Kompressor Merc, 2.0T A4 Audi...if you watch closely these models all make around the same bhp give or take + or - 10bhp between them. thier 0-60 mph is around the same + or - 0.5 to 1 sec between them. top speeds are around the same + or - 10 to 15 mph between them. and thier starting basic models cost around the same brand new + or - £5 to £10K depending on extra options available of course.. is it a fluke all these manufactures happen to achieve similar performance and price tag out of the 'Target Market' they designed the specific model for or there was more of them trying to be 'in line' with each other?? sure Audi alone could map the same 2.0T of the A4 to make an easy 260- 300bhp as that engine is pretty much the same as ones used in thier 06' S3 models but they held back.

fact that you have not done your reseach does not mean what i post is rubbish..feel free to put the non rubbish view of yours across the board.

and i still have my 4 door Normally Aspirated Supra of course..

[dave1]

That last line seems to prove your inability to be realistic.

[noby76]

Merry Christmas Dave :hohoho: