ISC vs G
Test drove the IS250C and the G37S conv. this past weekend, they feel like very different cars for a different target market. My wife's observation might be the best way to summarize it in one sentence: “The two cars are like beer and whiskey.” And she would be right (well, she’s always right). The G is a fun little ride, reminds me of the carefree days of college, and a great enabler for fun like a cold case of 24. The ISC is more mature, and like sipping whiskey, there are many details to enjoy.
I know the OP asked about power between IS350 and G37 so this won’t answer his question but hopefully this will come in handily for others.
Usable space is the biggest different I’d found between the two:
- In theory, the G can carry 24 beers in the trunk with the top down but in order to do will require some advance planning. Putting 4 boxes of 6ers will require the top to be up, remove the divider, put down the beer, replace the divider. But once the top is down, there’s no way to put more beer in or take them out. Alternatively, one can use the Pontiac Solstice method of putting one bottle in at a time.
- ISC on the other hand, looks like it would* easily fit 2 cases of 12 and still got room to spare. (*The wife wouldn’t let me bring a case of beer to the dealership so I had to improvise with a box of diaper. Can any current owner confirm the beer carry capacity of the ISC?)
- One negative about the IS is the trunk feels much heavier to close than the G
- ISC got more useable back seats, I’m 5’7”, fits in the back. My legs not pushing in the back of the front seat with my wife sitting in the front but there’s no place for my foot to move. I guess it’d be good enough if we go for an ice-cream run but 45min back there would be the max I would take.
- We tried putting a infant carrier in the back. In the G, the passenger seat has to move more forward than I’d like. The IS seems better for this but with the top up, it’s awkward to get the carrier in the back without opening the back window. (It’s a bigger Chicco seat) It wasn’t an easy task even without the baby in it, not sure if it’s possible with another 10~20lbs in that thing.
- ISC open/close about 10 sec quicker than the G, and looks like ISC has more moving parts.
- The G has 1 continuous piece of fabric for the root liner covering the gaps between the panels, versus you can clearly see where the gap is in the ISC when the top is up. However, in the G they put a stitching across the fabric to hold it into the root so it’s still not a smooth headliner like in their coupe.
- another interesting different, the switch for the top in the G is near the shifter, while it’s on the left of the steering wheel in the ISC. This means you can stand next to your car while you put the top up/down with the Lexus.
- The G I tested have reverse camera and the ISC got parking sensors in both the front and back. Sensors in the front is a great idea, and with trucks fit for Sir Mix-A-Lot, I'm leaning toward finding a car with Sat Nav and backup camera.
- Forgot to test parallel parking with the top up, my bad
- The G seat seems to feel wider, and it's nice that the instruments moves up/down with the steering wheel
- With the retracting steering wheel in the ISC, I'm not sure why anyone would upgrade to a flat bottom one other than for looks (having say that, that would be my second upgrade after putting in 2012+ headlights, Vanity: Definitely my favourite sin)
- I didn't test putting a cup in the cup holder but can someone tell us if the cup would get in the way of your elbow?
Gearing / Gas milage
- The G37s was a six speed manual, while the IS250C was a six speed auto, so aside from the engine these were very different cars I test drove. One thing to note, in the G the gas pedal is much deeper than the brake, it's very hard to heel and toe.
- seems odd to me but at 60mps, it seems that the G37 spins close to 500 - 800 rpm faster than the is250c. May be I should look up the gear ratios on both cars.
- From the bar graph readout the G seems to use the least amount of fuel while coursing at around 50mph, the ISC on the other seems to use less at 60mph then at 50mph. It's really hard to tell what's the MPG is with the stupid bars, couldn't they just display a number like in the RX?
- The Bose speaker on the head rest in the G sounds very nice even with the top down
- The base system in the ISC was alright, I wish I had a chance to try the Mark Levinson in it. I remember the M/L system sounds awesome in a LS I test drove many years ago.
- Driving back to back on the same road, you can feel the cowl shake in the G much more than in the IS. With the top up, the ISC wasn't bad but the G still feels like it's very unhappy with hitting bumps while in the curves.
- The interesting thing about the ISC is that with the top up, it feels very much like my RX350. It's nice and quite. All the layouts feel very logical. The one thing that I might need to get use to is my RX have the tech on the left, the ISC has it on the right. So I kept looking down for speed and kept getting RPM...
- if the OP is coming from a hybird, both might be disappointing for acceleration from stop. I find the even the CR-Z hybird I test drove a few weeks ago got better pick up from 0 to 35 (first 2 gears or so) than both the G37s and IS250C. The 250c doesn't want to wake up until past 50 mph, while the G37s kicks both asses going from 35 to 70 mph. I would like to try the IS350c but I couldn't even find a used IS350 at any dealer within 100 mile from here.