The explanation I can't quite pinpoint is the 0-60 times of the RWD 2IS to RWD 3IS.

If we take a look at the RWD 2IS to the AWD 3IS, the differences make sense. The RWD 2IS, with basically the same 6 speed as the AWD 3IS, runs to 60 in 4.9 to 5.1 seconds. The AWD 3IS does it in 5.3. Given that the AWD 3IS has additional drivetrain losses and 210 more pounds, I can see it running .2 to .4 seconds behind a RWD 2IS.

What I can't figure out is why the RWD 3IS is .5 second or more behind the 2IS. It makes me want to say it's the 8 speed transmission, but I don't know enough about it to understand what aspect of the transmission is causing this, given the drive ratio explanations above.

 

I believe R&T did a test on the 07 IS350 with Sport Pkg to produce the 0-60 time of 4.9 secs. In my recollection, all other tests that I saw for the 2IS were north of 5 secs. When shopping for my previous car (IS350), that particular R&T test made me search for a Sport model!

 

That's why I got 2008 IS350. I heard it is faster and same engine

 

It has to do with how many gears the 3is has to use to get to 60mph. Theres actually a few articles where the 2007 and 2008 is350 hit 0 60 in 4.9 with traction off. and with ppe headers, joez true dual, fsport intake. 4.5 seconds EASY. The 2is is ALOT quicker than people realize.

As far as 3is vs 2is and 0 60. Me and my friend(has 3is fsport ) have come to realize these simple facts. The 2is is faster stock in 1/4 and 0-60. The 3is pulls a bit better on highway (the 2is for instance is gutless after 90 mph really though 109 is whats quoted). The 3is handles better stock


as previously stated in this and other forums heres a jest of whats been repeatedly said

''Both have agressive gearing. Both have basically same 1st gear in regards to numerical transmission count 6 vs 8.
The 6th gear in the 2is and 8th gear in the 3is are over drive. The 2is shifts less to get to 60mph. The 3is pulls better up top where as a 2007 to 2013 is350 aren't really highway gunners.
The 3is would be better around a road course with its ISF 8 speed that has useable gear manipulating paddle shifters. The 2is has paddle shifters that arent that useful and just hold gears opposed as being able to shift them. the ISF 8 speed for the 306 hp 3.5 liter 6 cylinder is a bit over kill. This particular 8 speed was better matched with ISF"


all in all the 3is (especially the f sport) is a nicer better car even if it is in fact slower. It has a better transmission, better suspension updates, subjective styling that i like in some respects though i do really love the ''classic' simplistic styling my 2007 is350 has even if the dashboard melts lmao .

i personally won't trade in my 2007 is350 and make payments for a new is350 one (honestly not enough difference to be burdened with payments especially considering it is a tad slower). But i wouldn't turn down a free one

heres the vossen/kaira 2014 is350. Some love it some hate it. it def. looks exotic

 

^^^ Fair enough. As I recall the 6 speed can hit 60 in 2nd, while the 8 speed hits it in 3rd, meaning it has one additional shift (at 58 mph according to C&D) during the run up to 60 mph. I am just a bit surprised that one shift would impede progress by over half a second.

 

as jeff posted
2is 3is
1st: 14.37 / 14.40
2nd: 8.34 / 8.59
3rd: 5.72 / 5.84
4th: 4.08 / 4.59
5th: 2.91 / 3.86
6th: 2.38 / 3.13
7th: ---- / 2.58
8th: ---- / 2.15

 

you actually explained it perfectly when you showed the chart show numerical gearing,


The fact that the 8 speed has to shift a extra time to get to 60. That can definitely cost .4. Having to shift a extra time to get to 60mph (3 gear shifts opposed to 2.)

 

the 2is and 3is have very similar gearing.

But the 2is has 6 speed 4.08 final drive

and 3is has 8 speed 3.133 final drive.

In the 8 speed the 3.133 final drive is the rough non exact equivalent to a 4.08 in the 6 speed. This is partially why gearing in general is so similar. Though it causes the 8 speed to shift 3 times to get to 60mph.


Instead of equivalent you can install 4.09 final into the 8 speed(((((a really rough non exact example--- be kind of like 4.56 fd in the 6 speed)))))) .

The 3is and ISF Have same 8 speed.

Heres a forum where discussion about 4.09 in 8 speed ISF. Though won't be direct correlation to a 8 speed V8 when comparing 8 speed V6. 4.09 FD in the 8 speed makes 1st gear useless as a daily.

https://www.clublexus.com/forums/is-...50-diff-5.html

 

If you read some of the threads on the 3IS sub-forum, multiple owners will also note that the 3rd Gen IS350 does not have the same "throw you back in your seat" sensation that the 2nd Gen IS350 provides so I think it has more to do than just the extra gear shift.

Also, we if look at 1/4 mile times, the 2nd Gen IS350 continues to pull 'at best' times of 13.2-13.5 seconds stock while the 3rd Gen IS350 struggles to even crack 14.0 ( https://www.clublexus.com/forums/is-...for-is350.html). Would multiple shifts from the 8-speed account for this 1/4 mile time delta as well?

 

I rather have a 3rd generation. The handling is much better, it overlooks the small difference in acceleration from a stop. I think the 3rd generation has a faster rolling acceleration though.

 

Overall I also think 3rd Gen IS is better. Love the interior. If I have a choice I pick one up. But to me both exterior look good.

 

The 3rd Gen does handle better than the base model of the 2nd Gen but the 2IS F-Sport models can hold their own against the newer 3IS F-Sport.

Motor Trend provided this interesting handling comparison between the 2011 2IS F-Sport vs the 2014 3IS F-Sport:
http://www.motortrend.com/roadtests/...rt_first_test/

 

When I was looking at the gearing I didn't actually see that it would shift once more to get to 60, that would definitely explain some/most of the time difference.

Jeff

 

for sure

the 8 speed is overkill and messes with the 0-60 and 1/4 times.

the is350 306hp just isn't enough power for this ISF 8 speed automatic

It was way better suited to the ISF's 400hp+ V8.


Thst being said if people have a 3is and want better 0-60 and 1/4 times

Get a 4.09 FD gear. I linked the discussion on the subject on a previous post.


The ISF guys were using them and the ISF and 3is 8 speed are the same. I'm not sure everything that's involved but gears in general aren't a huge deal to install..

GS400/GS430 guys have been messing with higher FD (final drive) and high stall tq converters for years while having limited to no after market support.



the is350 community in general refuses to go past 12.8 in 1/4 lol.


Wth the fact looming that you can't reflash the ecu, most people use the is350 as a commuter/grocery getter.

 

I feel the biggest issue is the fact that it has an extra shift to 60mph. If you compared them to something just past when the 2IS has to shift to 3rd (65mph perhaps), I think you'd find they are much more comparable.

Aside from the very slight gearing change, the other thing is that the 3IS has a smaller tire size than the 2IS, which affects the effective gearing.

Jeff