jadeboy

iTrader: (1)

My 2007 IS 350 has been totaled. I am wondering if I should get another IS 350 (a later year but still used) or should I upgrade to the IS-F (used 2009+) for the extra cost.

I am seriously concern about the ride quality of the IS-F especially on long trip. I installed F-Sport Sway Bar into the IS 350 and hated the ride quality until I removed the front Sway Bar (left the rear alone).

I also know the 3rd gen IS is liking coming out this year too. But wouldn’t likely upgrade until it’s the 2nd or 3rd year of the 3rd gen.

bob4256

iTrader: (17)

If you really want more power and are willing to spend the money, I would say go for the ISF.

I cant speak much for the ride quality but after all it is a Lexus so it shouldnt be overly harsh. Im sure a few ISF owners can chime in here.

Good luck with your choice!

jmsharp02

iTrader: (2)

Take the ISF for a test drive. As far as long trips-you're going to be paying out the nose for gas mileage with the ISF most likely, though I doubt the is350 is all that much better.

lobuxracer

iTrader: (2)

If you didn't like the 350 with a swaybar, you'll hate the F. I traded my 350 for my F. It's not at all the same.

Gas mileage isn't that different from the 350. All time average on my 350 was 22.x, on my F it's 21.x.

Brake maintenance is the biggest difference for regular consumables. Everything else is pretty similar.

streetx

iTrader: (4)

Everything here, the F rides stiffer than the 350

Joeb427

iTrader: (1)

Go for a '10 IS-F..
I believe the '10+ has a bit softer suspension.
The pre '10 IS-F has a very harsh ride.

calvin2376

iTrader: (2)

Think about how often you've truly driven your IS350 to the edge, or taken full advantage of its power and performance. I'm going to imagine that unless you track it, it's been seldom. So do you need another 100 HP?

I have a 2007 IS350 and drive quite spiritedly, however I've never gotten close to maximizing the car's performance on public roads. So for me, there's just no need whatsoever for another 100 HP on top of 300 HP I can't fully take advantage of anyway. Particularly when it comes at a price tag of a few incremental thousand (at least) and lower fuel economy.

I'm surprised you found the ride to be so much worse after installing the F-Sport sway bars. I installed the rear F-Sport sway bar on my IS350 and noticed absolutely no change to the ride quality - only much reduced body roll.

dmvp29

I pretty much agree with this. I've owned an IS350 for 2 years now, and I actually had the privilege of test driving an ISF about 2 weeks ago. Going by my "butt dyno," the best way I can describe the relative performance of the IS350 and ISF is like this.

IS350 owners - I'm sure you all have realized this by now, but you can feel a marked difference in performance with the IS350 if it's a nice, cold day (and you have low gas, say around 1/4 tank) versus a very hot day with a full tank of gas.

If you've ever try to go WOT from 0 in 40-50 degree weather with 1/4 tank gas versus 90-100 degree weather with a full tank, you can REALLY feel a difference.

To me, the ISF on a hot day feels like the IS350 on a very cold day (with low gas). I did not get a chance to drive the ISF on a cold day, but I'm sure it would've felt a bit peppier. And honestly, the numbers I've seen agree with my "butt dyno" conclusions.

With 1/4 tank gas and ideal (cold) weather, an IS350 can pull low 13s in the 1/4 mile. The ISF can conceivably reach into very very low 13s if weather conditions are not ideal (i.e. very hot). Otherwise, the ISF's optimal 1/4 mile is really around mid 12s.

You (topic creator) also have to realize that the difference between the ISF and the IS350 is not even close to the difference between the IS350 and the IS250. "Performance" does not increase linearly with horsepower. You end up with diminishing returns.

IS250 1/4 mile = 15.5 seconds
IS350 (+100HP) 1/4 mile = 13.5 seconds (2 second improvement)
ISF (+100 HP) 1/4 mile = 12.5 seconds (1 second improvement from IS350).

Will I still jump on an ISF when prices are reasonable? Sure, why not. Granted, I'd never use the performance but if the price is right a 1-3 years down the road, the ISF is a solid bet.

Performance aside, the one thing I like about the ISF is that it has REAL paddle shifters and a true manumatic mode.

I'm not pining for the performance of an ISF but one day when the price is right, I wouldn't mind upgrading. I think there's a much stronger rationale to go from an IS250 to an IS350 because 100 HP simply means more (performance-wise) at that level.

jmsharp02

iTrader: (2)

The biggest reason I'd go for an ISF is stated by dmvp29-the "true paddle shifting." Really in the end that's the biggest difference for me.

dmvp29

Oh yeah, I also have F-sport sway bars (front and rear) on my IS350, and I agree the ride is "harsher" but this is the hallmark of a true luxury sports car. You get to feel every bump and aberration on the road. This is the type of "feedback" that sports car enthusiasts PINE for.

The IS350 is not a grand tourer/luxury cruiser so why would anyone expect it to ride super cushy and comfortable with F-sport sway bars? It's supposed to be rough. You can really toss the IS350 around with sways.

The ISF, like the IS350 (with F-sport sways), also has a harsh ride, but I did not mind it at all. It's exactly what I expected, and I appreciate the sort of feedback the ISF provides during spirited driving.

Dragtek

iTrader: (2)

I'm in the same boat, but I'm more then likely going to end up with the ISF. I don't want to regret not getting the car I wanted in the first place and settling for a 350 (although it's still a great car). However, this car won't be a daily for me so the ride quality is not an issue.

dmvp29

Here's a good video where you can actually see the straight line performance difference between the IS350 and ISF -

http://www.youtube.com/watch?v=rFTj5WpVICY

The ISF is consistently faster, of course, but by an average of about .6-.7 seconds through the 1/4 mile (barring the one run where the IS350 jumped the gun and then hesitated (braked) and then went).

dmvp29

By the way, just a disclaimer, everything I said is for DAILY DRIVING purposes. I'm not talking about going around the track. The ISF would spank the IS350 around a track, there's no question about that.

For daily driving purposes, most people keep it within the 0 to 100 MPH range. The video above illustrates the difference between 300 and 400 HP within (roughly) this range, as the ISF's 1/4 mile trap is around 110 while the IS350's trap is around 102-103 MPH.

EDIT: And, by the way, the IS350 is on SNOW TIRES while the ISF is on R comp slicks. Give the IS350 slicks, and its times would conceivably improve by another few tenths of a second.

laobo979

iTrader: (5)

IS-F hands down

ISF4life

iTrader: (30)

ISF and i approved this message