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I don't want this to become a feed the troll thread but the differences between these two cars are minuscule with regard to weight and packaging. The only significant factor is the wheelbase and the suspension tuning. The information you present is correct in general, but look at the specifics between these cars... I've listed GS numbers first, IS second
Track Width F/R:
62/62.6
60.4/61
Passenger hip room
54.5/54.1
54.3/54.0
Height:
57.3 in
56.3 in
Tire + Rim Radius:
13.2 in
12.5 in
Fuel Tank Size
17.4 gal
17.4 gal
Curb Weight
3.7k
3.6k
Wheelbase
112.2in
110.2in
Overall Length
190.7 in
183.7 in
Trunk Cargo Volume
14.1 cu ft
13.8 cu ft
The difference in height is almost entirely due to differences in tire size, not chassis ( I'd imagine the remainder is due to the static height of the springs ). The absolute difference in weight is almost negligible, same with the trunk cargo volume. The engine and transmission are identical. The track widths are different by a couple inches but I'd bet this is due to the length of the control arms and not the chassis as the hip room is identical.
It's the same car with one significant difference in the wheelbase; as I'd imagine the front clip is near identical this puts the engine of the GS around 1 in further in front of the center of the wheelbase than the IS and likewise the gas tank ~ 1 inch further from the wheelbase center than the GS.
The suspension tuning( roll centers of the front and rear suspension/bushings/shocks/dampers) and wheelbase is all that's at play here... there is no significant difference in the packaging, weight distribution or any other significant structures aside from the affect of a 2in longer wheelbase. There may be a significant difference in the designed roll centers of the front and rear suspension which would be critical but that's something neither of us will know =)
We're basically comparing a prototype sedan to the finished product; we're not comparing a corvette to an M5!
All that being said, the IS does drive a bit nimbler from the factory and ride harsher, but it's largely the result of that damn compliance bushing on the front suspension arm on the GS being so loose. When you change that out they're pretty similar in terms of ride and response with the only difference I've noticed is a tendency for the GS to oversteer slower than the IS. I've had no issues in catching, controlling or sustaining the slide in either car.
The biggest difference I've seen between the two largely lie in their interiors to be honest. The driving dynamics are not different unless your doing really stupid things on public roads which I'm not immune to
Haven't driven a IS, but to me the car is so much smaller inside.
Originally Posted by sarmyth
Peteharvey,
I don't want this to become a feed the troll thread but the differences between these two cars are minuscule with regard to weight and packaging. The only significant factor is the wheelbase and the suspension tuning. The information you present is correct in general, but look at the specifics between these cars... I've listed GS numbers first, IS second
Track Width F/R:
62/62.6
60.4/61
Passenger hip room
54.5/54.1
54.3/54.0
Height:
57.3 in
56.3 in
Tire + Rim Radius:
13.2 in
12.5 in
Fuel Tank Size
17.4 gal
17.4 gal
Curb Weight
3.7k
3.6k
Wheelbase
112.2in
110.2in
Overall Length
190.7 in
183.7 in
Trunk Cargo Volume
14.1 cu ft
13.8 cu ft
The difference in height is almost entirely due to differences in tire size, not chassis ( I'd imagine the remainder is due to the static height of the springs ). The absolute difference in weight is almost negligible, same with the trunk cargo volume. The engine and transmission are identical. The track widths are different by a couple inches but I'd bet this is due to the length of the control arms and not the chassis as the hip room is identical.
It's the same car with one significant difference in the wheelbase; as I'd imagine the front clip is near identical this puts the engine of the GS around 1 in further in front of the center of the wheelbase than the IS and likewise the gas tank ~ 1 inch further from the wheelbase center than the GS.
The suspension tuning( roll centers of the front and rear suspension/bushings/shocks/dampers) and wheelbase is all that's at play here... there is no significant difference in the packaging, weight distribution or any other significant structures aside from the affect of a 2in longer wheelbase. There may be a significant difference in the designed roll centers of the front and rear suspension which would be critical but that's something neither of us will know =)
We're basically comparing a prototype sedan to the finished product; we're not comparing a corvette to an M5!
Originally Posted by sarmyth
All that being said, the IS does drive a bit nimbler from the factory and ride harsher, but it's largely the result of that damn compliance bushing on the front suspension arm on the GS being so loose. When you change that out they're pretty similar in terms of ride and response with the only difference I've noticed is a tendency for the GS to oversteer slower than the IS. I've had no issues in catching, controlling or sustaining the slide in either car.
The biggest difference I've seen between the two largely lie in their interiors to be honest. The driving dynamics are not different unless your doing really stupid things on public roads which I'm not immune to
Yes Sarmyth.
There is only 1" difference in height.
1-2" difference in width.
2" difference in wheelbase.
Yet there are those like e60BMW who agree that it translates to so much difference in space inside.
And just as much difference in dynamics and NVH.
Yet there are grandmothers & untrained eyes out there who think both 3IS and 4GS look the essentially the same outside, feel essentially the same inside, and drive essentially the same.
It just depends where you're coming from...
Yet there are grandmothers & untrained eyes out there who think both 3IS and 4GS look the essentially the same outside, feel essentially the same inside, and drive essentially the same.
It just depends where you're coming from...
You can count me in the group of "untrained eyes" who think they drive the same. Yes, there are differences on the autocross course, but in day to day and even spirited driving, I found them to be incredibly similar in handling.
You can count me in the group of "untrained eyes" who think they drive the same. Yes, there are differences on the autocross course, but in day to day and even spirited driving, I found them to be incredibly similar in handling.
And to people like you, the cabin space and NVH are just as incredibly similar too.
That's life - there are always going to be people who feel like that...
And to people like you, the cabin space and NVH are just as incredibly similar too.
That's life - there are always going to be people who feel like that...
That's quite a generalization. I'm not sure what I said about the handling of the two cars makes you so certain that you know how I feel with regards to their interior volumes or their NVH.
I traded in my IS specifically because I wanted the larger interior volume of the GS, so it seems to me that your generalization of how I feel about that is incorrect.
If you'd like to learn more about me you can look at my posting history and see my comments regarding NVH between the IS and GS. It should be clear from that that I don't view them as the same.
I would politely request that you consider other people have opinions and experiences that are different from yours that have nothing to do with them being untrained or less knowledgeable than you.
That's quite a generalization. I'm not sure what I said about the handling of the two cars makes you so certain that you know how I feel with regards to their interior volumes or their NVH.
I traded in my IS specifically because I wanted the larger interior volume of the GS, so it seems to me that your generalization of how I feel about that is incorrect.
If you'd like to learn more about me you can look at my posting history and see my comments regarding NVH between the IS and GS. It should be clear from that that I don't view them as the same.
I would politely request that you consider other people have opinions and experiences that are different from yours that have nothing to do with them being untrained or less knowledgeable than you.
Like I said JDR, let me be clear - there are going to be people who think the 3IS and 4GS look remarkably similar.
There will also be people who think the 3IS and 4GS are remarkably similar in dimension, differing by only 1" height, 1-2" width, and 2" in wheelbase.
There will also be people who think 3IS and 4GS are remarkably similar in handling and refinement.
There will be those who think the two cars are remarkably similar.
There will be those who think the two cars are noticeably different.
Each to their own.
Relax buddy. Let it be...
... Below is a sports car and a sedan of the same mass/weight. Because the sports car is shorter and narrower with its mass concentrated towards the center, it has a lower polar moment of inertia, hence greater agility - it increases the speed of change in direction compared to the sedan on the right.
EXCELLENT & INFORMATIVE @ peteharvey backed up by evidence. I think you hit the nail on the head. Are you an engineer or similar?
I'll consider the new IS350 FSport my sports CAR on the left, and the old GS300 my sporty SEDAN on the right!! Forget to mention in the OP that the IS has 18" wheels, and GS has 17" (I THINK). IMO, despite "FSport" features, Lexus tries to incorporate & instill "luxury driver car" into IS models versus "luxury sports sedan" into GS models. On a purely subjective scale the GS more so gives one a sense of accomplishment, whereas the IS just MAKES you feel young again! lol
Here's an email I got from professional car review//test drive folks:
We've driven the GS350 F sport. It's also surprisingly good - but as you surmised, it's quite a bit bigger and definitely feels like it. The GS is a big performer like in the M5 class. If I were going to buy a car to hoon on a back road, I'd pick an IS over a GS. If I were going to blast down the autobahn or drive cross country, I'd probably pick the GS.
On another note, it seems like some of the strictly GS owners on this thread seem to be a tad sensitive ...
EXCELLENT & INFORMATIVE @ peteharvey backed up by evidence. I think you hit the nail on the head. Are you an engineer or similar?
I'll consider the new IS350 FSport my sports CAR on the left, and the old GS300 my sporty SEDAN on the right!! Forget to mention in the OP that the IS has 18" wheels, and GS has 17" (I THINK). IMO, despite "FSport" features, Lexus tries to incorporate & instill "luxury driver car" into IS models versus "luxury sports sedan" into GS models. On a purely subjective scale the GS more so gives one a sense of accomplishment, whereas the IS just MAKES you feel young again! lol
Here's an email I got from professional car review//test drive folks:
On another note, it seems like some of the strictly GS owners on this thread seem to be a tad sensitive ...
No, I'm not an engineer, but I was going to study mechanical engineering some 35 years ago.
Back in the 1980's, I used to love compact cars, and dumping the car around corners, intersections and roundabouts, but I don't do that much anymore.
These days, I'm more sensitive to ride, refinement and noise/vibration/harshness - hence I prefer midsize cars, but the missus prefers compacts because they are noticeably easier to drive and park.
The GS350 F Sport actually has 19" asymmetrical alloy wheels, slightly wider and taller side walled, but the same profile as the IS350 F Sport.
The main point is that even when two cars are similar in weight because they are derived from the same platforms, and they share the same driveline, the smaller size vehicle has a smaller polar moment of inertia, and hence greater agility.
Everyone wants to be proud of what they own.
However, my comments on the magnitude in differences between the IS and GS was based on the "context" of the Opening Post.
If you were a 70 year old grandma, or someone with very little interest in motor cars at all, then there would be little if any difference between the IS and GS.
However, because you seem to be somewhat an enthusiast, and you deliberately asked for an opinion on dynamics as opposed to comfort, you would be more sensitive, and you would understand the magnitude in difference between the IS and GS - from your perspective.
... The GS350 F Sport actually has 19" asymmetrical alloy wheels, slightly wider and taller side walled, but the same profile as the IS350 F Sport.
What I meant was my old GS300 has 17" wheels and the tires are MUCH MORE taller side walled versus 18" wheels on the newer 3rd gen IS350 FSport. Do ya have any scientific comments/data regarding this?
I would very much like to get taller side wall tires on the IS350 however after speaking with the dealer service manager, he said this might require re-configuration of several wheel components, which in turn will mess up the computer detection systems on the car.
If you were a 70 year old grandma, or someone with very little interest in motor cars at all, then there would be little if any difference between the IS and GS.
"little ole lady from Pasadenaaaa"... Actually, when I get to be a 70 year old grandPa I HOPE to CONTINUE noting performance variances regardless of the cars I'm hot rodding around in!!
I would very much like to get taller side wall tires on the IS350 however after speaking with the dealer service manager, he said this might require re-configuration of several wheel components, which in turn will mess up the computer detection systems on the car.
Yes, it may be difficult.
The overall rolling diameter of the tires must be similar.
Instead of Plus 1 or Plus 2, you would have to downsize the alloy wheels and Minus 1 or even Minus 2 to 17" or 16" respectively, and this would probably not clear the large diameter of the front brake rotors.
If you're interested in both handling and ride balance, then you may have to buy an used 2013-2016 inclusive 3IS350 F Sport, as opposed to the brand new 2017 IS350 F Sport.
I have test driven both thoroughly, and to my surprise, the mid-life updated 2017 IS350 F Sport doesn't have a nice a ride as the original 2013-16 build date versions.
My wife used to own the 2014 IS250 F Sport with 18" asymmetric wheels on Dunlop SP Sport Maxx 050 tires.
The original F Sport models have a lovely ride despite their 18" 40% profile front and 35% profile asymmetric rears.
I consider myself very sensitive to ride, and the original model had a surprisingly lovely ride, and I wouldn't bother changing its formula.
However, the new 2017 IS F Sport has a "knobby-like" ride; I'm not sure what they changed in the spring/damper/roll bar rates, but they use the same Dunlop Sport Maxx 050 tires.
May be there is too much damping control on the mid-life update? Not sure. I would have to spend more time test driving to determine exactly what is different.
_
... I have test driven both thoroughly, and to my surprise, the mid-life updated 2017 IS350 F Sport doesn't have a nice a ride as the original 2013-16 build date versions. My wife used to own the 2014 IS250 F Sport with 18" asymmetric wheels on Dunlop SP Sport Maxx 050 tires. ... However, the new 2017 IS F Sport has a "knobby-like" ride; ... they use the same Dunlop Sport Maxx 050 tires. ...
Interesting >>> the ride difference on the 2017 IS models.
Also interesting is the mention several times of “Dunlop SP Sport Maxx 050” which is also surprising --- I thought all IS stock/OEM came with Bridgestone® Turanza ER33 (which btw kind of suck).
I will soon be staggering the OEM Bridgestones with a pair of (think I’ll go with) Michelin Pilot® Sport A/S 3+ on the front, then later match up the rear with the same.
Interesting >>> the ride difference on the 2017 IS models.
Also interesting is the mention several times of “Dunlop SP Sport Maxx 050” which is also surprising --- I thought all IS stock/OEM came with Bridgestone® Turanza ER33 (which btw kind of suck).
I will soon be staggering the OEM Bridgestones with a pair of (think I’ll go with) Michelin Pilot® Sport A/S 3+ on the front, then later match up the rear with the same.
The IS200t base models like my wife's has the new Bridgestone Turanza T001's touring [sporting-luxury] which are very soft and comfortable on the sidewalls; dare I say, even softer than my Pirelli Cinturato P7 A/S Plus!
However, if I remember correctly, the IS F Sport models use Dunlop SP Sport Maxx 050 sports tires.
Turanza ER33's are very old tires, and they are also touring tires, rather than sports tires.
All that being said, the IS does drive a bit nimbler from the factory and ride harsher, but it's largely the result of that damn compliance bushing on the front suspension arm on the GS being so loose. When you change that out they're pretty similar in terms of ride and response with the only difference I've noticed is a tendency for the GS to oversteer slower than the IS. I've had no issues in catching, controlling or sustaining the slide in either car.
The biggest difference I've seen between the two largely lie in their interiors to be honest. The driving dynamics are not different unless your doing really stupid things on public roads which I'm not immune to
Just curious about the comment on the "compliance bushing on the front suspension arm on the GS being so loose." What part or part number is that, can it be changed, and what is the effect of changing it? I have had both a '15 GS non-F, and now a '16 GS F Sport, and I find both cars to exhibit a lot more dive forward when braking than I like. Would changing this part have any effect on that?
07-06-17, 08:40 AM
