I am currently looking in to the RC350, IS300, and IS350. I've tried looking for differences between the 300 and 350, specifically F sport for both, but think it's made me more confused and what appears to be changing nomenclature is not helping. It seems like the only difference is that the 350 is quicker, but that the 300 can be brought up to 350 stock speed with a tune? Are there any other differences between the two, interior or exterior? I live in So Cal so don't need AWD.

 

There are two different engines for the 300 depending on whether you get AWD. The 300 with RWD has a turbocharged 2.0-liter four cylinder. The 300 with AWD has the same 3.5-liter V6 as the 350, but tuned to a lower output.

If you have a 2017 and earlier 300 AWD you can tune it to match/slightly exceed the 350's output. There's a whole thread on the CL Vendor Products for 3IS section about it.

edit: Also worth noting, the 350 F Sport is available with Adaptive Variable Suspension, whereas the 300 is not.

 

In both the RWD IS300 and RWD RC300, they have the 2.0t 4 cylinder, so they cannot be brought up to the 350 version with a tune.

The AWD IS300 and the AWD RC300 use the same V6 as the 350, just tuned for less power.

 

Ah, another difference I remember reading about it. Would you saw the AVS is worth it?

 

Honestly, from an upgrade perspective, I didn't find the F-sport was really worth it unless you got the 350 because AVS is pretty damn good. But many like the cosmetic upgrade from F-sport so its worth it for them. Another thing to note is that the IS350 RWD gets an 8-speed which is an upgrade form the 6 speed. The most performance oriented is definitely the 350 F-Sport RWD. Did you test drive the 2L turbo? Its pretty slow so I'd stick to the 3.5L.

 

There's no debate on this. 350 is always superior to any 300. particularly if you're buying used. 350 is always the best 3is. the only question is whether you are willing to pay more for it.

 

2018+ 300 AWDs cannot be tuned at this time? Or they haven't cracked the ECU code yet?

Never mind, I see that the IS got the 2GR-FKS for the 2018 model year.

 

The IS300 V6 is the 89 octane of the 3IS lineup.

 

This has been discussed many times before,
but if I understand, the NA 350 only kicks in over
4,000 rpm versus the NA 300. So for driving in town, you might not notice
the difference between the AWD 300 and AWD 350.

 

I test drove a 2018 IS 350 AWD, and for whatever it's worth, I didn't feel any seat-of-the-pants difference between it and my 2016 300 AWD. I'm sure on paper, and with proper measurements, it wins by 0.3-0.4 seconds in a 0-60 run, but I don't know if you'd notice as the driver. There was also a recent thread on the forums with back-to-back 0-60 runs in the 300 AWD and 350 AWD, both 2016, and there was less than 0.2 seconds separating them.

 

Thanks Arentz07.
Glad to hear that, again.

 

Did you feel that the transmission shifts pretty quick in sport+ and in manual (ie. paddle shifter mode)?

 

When I drove the 2018, I only really was able to drive it for a few minutes, so I didn't get a chance to play with the paddles. But, I don't expect the transmission to be any different in the 2018 versus the 2016. In my 2016, the transmission shifts much quicker in the manual "M" shift mode than when left in "D" drive. The owner's manual says Sport makes it shift more quickly, but I don't buy that. It really only feels different in M versus D. TBH I've driven a few cars with newer transmissions, like the Stinger and the 3-series, and I think the 6-speed in the AWD IS models is pretty lackluster compared to those. However that doesn't mean it's not fun. It will hold gears when you're in Sport, and it can bang off the rev limiter when you have traction control fully off. For a transmission from 2005 it's not bad.

edit: By the way, all of what I just said applies whether you get a 350 or a 300. They have the same transmission.