natnut

I just thought that it would be interesting to compare how the 2013 GS350 fares against the IS350 considering that they both have the same engine and the IS350 is 300lbs lighter. I added the ISF just to compare the new GS against a full-fledged super-sports sedan.

I got the numbers from Motortrend website and compared the 2013 GS vs the 2006 IS350 and 2008 ISF. I'm very impressed with the improvements in the GS. The few things that stick out to me is that the GS(F-sport) was able to match the 300lbs lighter IS350 in straight-line acceleration and beat it in handling and match the ISF supersedan in terms of lateral g and slalom times.

Essentially, a 2013 GS F-sport owner is getting an ISF (in terms of handling) with the added space and utility of a car 1 class larger and at a cheaper price to boot.

**I'm assuming the current IS350 and ISF haven't changed much from their 2006 and 2008 iterations.

UPDATE 1:
I've been reading that the current generation F10 535i loses to the GS350 in performance/handling due to its massive weight gain of 400pounds from the previous generation E60 535i. And that the E60 5 series was a much sharper drive drive compared to the F10 5 series.

So I thought it would be interesting to compare the E60 535i M-sport against the current handling champion in its class, the 4th generation GS350 F-sport. Here's the numbers from Motortrend :

GS350 F-sport :
weight 3825lbs 0-60 5.5s 1/4mile 14s@100.9mph 60-0 105ft skidpad .91g slalom 25.7s

E60 535i M-sport :
weight 3844lbs 0-60 5.5s 1/4mile 14.1s@100.6mph 60-0 112ft skidpad 0.85g slalom 26.5s

As we can see, Lexus really did their suspension tuning homework as the 4th gen GS still beats the similarly lightened E60 535i.

UPDATE 2 :
For interest I also added the F10 535i and 550i performance numbers and they're all in the updated attached document.

Of note is that the weight of the heavy V8 in the nose of the 550i REALLY penalizes the 550i's handling. Despite the massive advantage in hp/torque and far better 0-60/quarter mile times, it was still half a second slower than the GS350 in the slalom.

Another interesting point is that Motortrend NEVER tested the slalom time of the F10 535i or else never published it. I wonder if BMW deliberately leaned on MT to suppress such information as it didn't want the F10 to look bad next to the older E60.

UPDATE 3 :
Thanks to JoeZ's suggestion, I also checked the 2012 ISF with its overhauled suspension and Torsen LSD. Now I want a 2012 ISF LOL

From Motortrend :

2012 ISF
weight 3778lbs 0-60 4.5s 1/4mile 12.9s@111.4mph 60-0 105ft skidpad 0.96g slalom 24.8s@0.79g
Compared to
2008 ISF
weight 3805lbs 0-60 4.3s 1/4mile 12.7s@113.4mph 60-0 108ft skidpad 0.91g slalom 25.1s@0.77g

Comparing the 2013 GS350 F-sport to the 2012 ISF, one thing stands out : it might be worth the price to get the F-sport package just for the brakes alone, the 2013 GS350 F-sport matches the 2012 ISF in braking 60-0 (both 105ft) and reviews have stated that the F-sport brakes are highly resistant to fade with repeatable performance despite multiple hard braking. The GS350 F-sport might well be the best stock brakes in a mainstream production sedan.

(I've also added the 1/4 mile trap speeds as several CL members have told me it is a better indication of engine performance than just 1/4 mile times alone.Wherever possible, I've also added the average lateral g of each Slalom test.)

Dema

I can give you another perspective
ES is more family car, most drivers are females, fwd can make the car better in snow when fwd version isn't available. Some people consider it as luxury Camry, so certainly sporty aspect of ES is out of consideration
IS is entry level luxury sedan (and now coupe and convertible as well) the car is more suitable for young unmarried males and females,

Hoovey689

iTrader: (16)

Interesting topic OP. What did the IS and GS trap at is more important than their 1/4. The IS should be higher. What most impressed me when I first read it too was the slalom time between the GS and IS-F. Lexus finally got the tuning right, but these numbers are a bit dated because the 2011 ISF was retuned and did considerably better than its 2008 counterpart. Within the year when the next IS is released, it will be interesting to see how the IS and GS compare. As it stands with these numbers, I'm not all that surprised the newer GS comapres well against the older IS. I test drove a 2013 F-Sport yesterday with Sport+ and Dynamic rear steer, and the GS was a monster on hard turns and the onramp.

LexFather

I said it back in November, the GS 350 F-sport with rear steer IMO handled better than the 08-09 IS-F. I need to compare to the revised suspension model but I honestly think that rear steer helps amazingly.

dsadsauser

The IS350 does waaay better than 14 Sec in the QM. I did 13.6 on a hot summer day.

spwolf

I cant wait for 2014 IS :-). It should be even better.

natnut

UPDATE :

I've been reading that the current generation F10 535i loses to the GS350 in performance/handling due to its massive weight gain of 400pounds from the previous generation E60 535i. And that the E60 5 series was a much sharper drive drive compared to the F10 5 series.

So I thought it would be interesting to compare the E60 535i M-sport against the current handling champion in its class, the 4th generation GS350 F-sport. Here's the numbers from Motortrend :

GS350 F-sport :
weight 3825lbs 0-60 5.5s 1/4mile 14s@100.9mph 60-0 105ft skidpad .91g slalom 25.7s

E60 535i M-sport :
weight 3844lbs 0-60 5.5s 1/4mile 14.1s@100.6mph 60-0 112ft skidpad 0.85g slalom 26.5s

As we can see, Lexus really did their suspension tuning homework as the 4th gen GS still beats the similarly lightened E60 535i.

For interest I also added the F10 535i and 550i performance numbers and they're all in the updated attached document.

Of note is that the weight of the heavy V8 in the nose of the 550i REALLY penalizes the 550i's handling. Despite the massive advantage in hp/torque and far better 0-60/quarter mile times, it was still half a second slower than the GS350 in the slalom.

Another interesting point is that Motortrend NEVER tested the slalom time of the F10 535i or else never published it. I wonder if BMW deliberately leaned on MT to suppress such information as it didn't want the F10 to look bad next to the older E60.

(I've updated my original post with the new information and attached documents)

Liferules

Great details, Natnut! Makes me like the 4GS even more.

Joe Z

iTrader: (10)

Natnut,

Can you see if you can modify your data to include the latest 2012 IS-F ??

It did have some major suspension re-tunning from some of the LFA Engineers..

~ Joe Z

natnut

WOW, the 2012 ISF is a beast!

From Motortrend :

2012 ISF
weight 3778lbs 0-60 4.5s 1/4mile 12.9s@111.4mph 60-0 105ft skidpad 0.96g slalom 24.8s@0.79g

Compared to
2008 ISF
weight 3805lbs 0-60 4.3s 1/4mile 12.7s@113.4mph 60-0 108ft skidpad 0.91g slalom 25.1s@0.77g

kinglexus99

The avg 0-60 for an IS350 '06 to '12 is 4.9 seconds not 5.5. It wouldn't physically make sense that a car weighing 300lbs more would be at the same pace as the lighter car especially with the same engines.

ECL

There is an IS Coupe?

dseag2

No, you haven't missed anything. Still only the sedan and hartop convertible.

peteharvey

Can I ask if you have actually driven the IS350 before Natnut? Back to back with a 4GS?
Let me know if you travel overseas much at all?
I would be more than willing to loan you my IS250 for a weekend if you venture overseas.

The IS350 is not only significantly lighter than the new 4GS350, but it is also considerably shorter in wheelbase and length.
The difference between the IS and 4GS in width is minimal, and in height is very minor.
When people ask why cars mainly differ in length, and not in width or height, its because we humans mainly differ in leg length and therefore height, as we get taller.
We differ little in width.
Because we sit inside a car, and the legs point forwards, cars mainly differ in length, and not in width or height.
That increase in width is actually for the 5th seat.
When we fellow humans sit next to each other, there is little difference in torso length, hence there is little difference in the height of the motor car.

Because the difference is mainly in weight, and in length, it affects the polar moment of inertia.
The greater the polar moment of inertia, the slower the "yaw", in other words, the slower the ability to change directions.

You will find that the IS250 changes direction much faster than the IS350, and that in turn much faster than the 4GS F Sport that I drove last weekend, especially if we compare the same IS F Sport version to a GS F Sport version.
The IS-F V8 versus the 4GS F Sport is a tougher and closer comparison, and the result depends; either could win.


Measurement Human Error Factor
2012 ISF
weight 3778lbs 0-60 4.5s 1/4mile 12.9s@111.4mph 60-0 105ft skidpad 0.96g slalom 24.8s@0.79g
Compared to
2008 ISF
weight 3805lbs 0-60 4.3s 1/4mile 12.7s@113.4mph 60-0 108ft skidpad 0.91g slalom 25.1s@0.77g

Look at the degree of human error here.
It just goes to show how they are not exactly comparable.
Who is starting and stopping the stop watch? Human hands, or an electronic sensor???

So too, the Motortrend data for the IS350 is not accurate.
Even Lexus own data says that the IS350 does 0-60 mph in 5.6 versus the GS350's 5.7 seconds.
I have driven the IS350 about 12 months ago, and the nose isn't much heavier than the IS250.
The heavier GS almost matches the IS350 in linear acceleration.
However, model for model, the IS will still change direction faster than the GS, with more terminal grip than the GS.


The IS-F V8 has bags of linear acceleration, going from 0-60 in under 5 seconds, however when it comes to handling and breaking, the heavier V8 in the IS-F's nose works against it.
Here, the F Sport can actually superior.
I have never test driven the IS-F.
However the old 3GS in V8 handles terribly compared to the old 3GS in V6.
A nose heavy car will never handle as well as a nose light car.
When we test drive a Benz C250 2.0 Turbo against a C300 3.0 V6, the 4 cylinder version always has the lighter nose, the faster turn-in, and the higher terminal grip.

As for the Motortrend slalom, g-force, and braking distances, both the 4GS F Sport and IS-F must be measured on the same day for the data to be comparable.
And it also depends who presses the stop watch, human hands, or an electronic sensor?
The error in the human thumb and reaction times is considerable.


You are right.
The old smaller lighter 5 Series out-handles the bigger heavier current model.
And the F Sport seems to subjectively out-handle the 535i M Sport, according to our test drives...

natnut

Your points are well taken.

However, don't forget that the presence of Dynamic Rear Steer (DRS) in the GS F-Sport tested by Motortrend. Rear Steer in essence works by reducing the effective wheelbase/length of the vehicle as it turns around a corner. That is one reason (other than the superior suspension of the 4GS as compared to the 2IS) why the 4GS behaves like a smaller car and is faster than the IS350 on the handling circuit. So simply comparing physical wheel-bases/lengths may be misleading.

Secondly, if you watch this website where Motortrend and Automobile magazines conduct their testing, they apparently use Vbox testing which seems to mitigate human error :

http://www.automobilemag.com/lexusgschallenge/

Other than that, you won't get any arguments from me about the nose-heaviness of a V8 spoiling the handling of a car. Weight in the nose is never good.