yodair8

Hello!

I recently traded out of two hondas into a new IS 300 AWD and an NX200T.

So far I'm loving the cars, but I wanted to ask for a bit of advice. I can't seem to find anything marketed to the 3IS 300 AWD in regards to performance or any sort of modifications. There was a nice write up from RRacing on this forum that was talking about tunes and left me with an impression that the 300 AWD is really a 350 with a weak tune on it. If that is true, can I shop for 350 parts and assume they will fit my car?

Any advice is warmly welcomed. Thanks.

Sasnuke

The IS300 and IS350 basically have the same 3.5L engine except that the 350 has port and direct injection, and the 300 has only direct injection.
Although the vast majority of parts that fit a 350 will also fit the 300, unfortunately it's not a ll parts and you'll need to confirm those few that are just 350 specific.

JDR76

This is not quite correct. Both the IS300 and the IS350 use the exact same engine, both with port and direct injection. It's just the ECUs are programmed differently.

Sasnuke

I guess the old internet is not always right. One site says it has direct and another says it has both.
If it has both, then...for me at least...it doesn't justify the difference in price and performance.
I wonder if an ECU swap might be possible to regain that 50 horsepower/torque.

JDR76

Always best to go to the source.

You can get some pretty good, detailed specs here:

pressroom.lexus.com/releases/2017-lexusis-sedan-product-specifications.download

Here is a thread discussing an ECU IS300 to IS350 swap:

https://www.clublexus.com/forums/is-...h-350-ecu.html

yodair8

Thanks so much for the replies! Yeah I understood them to be the same, there's a tune from RRacing that I'll be doing that closes the gap.

Another question for you guys if you're up to it. I've had new cars before but it's been awhile. What is the break in period for the Lexus? Should I be focusing on anything? Swapping the manufacturers oil? Any tips along those lines?

Much appreciated.

JDR76

As I recall from the manual, the break in period is pretty simple. Easy acceleration and braking for the first 1000km/610 miles. First oil change recommended at 10k miles. They don't recommend the oil change after the first 1000 miles like they used to due to better manufacturing processes.

computerwi

Welcome to Lexus, and ClubLexus! You'll have a blast with both vehicles. I owned that exact combination before and it was perfect if you have a smaller family/younger kids.

Toyota ECUs are notoriously difficult to tune. Make sure you find someone who knows what they're doing. If something goes wrong, best case is that the tune did nothing and you just wasted some money. Worse case, well, your car could be crippled. This will void your warranty so it's all your own risk of course.

On another note, I never understood why Lexus bothered to produce the IS 300. Why put in the same mechanical components and use software to de-tune it without any improvement in fuel economy...

arentz07

My guess is to provide a cheaper, but more desirable than the IS 250, AWD version of the vehicle compared with the IS 350 AWD. It costs a few grand to make the jump from IS 300 to IS 350 AWD. I agree, it is somewhat shady, but nothing that new RR tune can't fix, eh?

The difference in power is not going to be noticeable unless you're really hammering it, as in, above 4500 RPM the power doesn't seem to come on as strong. In town at tamer speeds, it feels smooth, eager, and never overworked.

As you might guess I like my IS 300 so far - had it for 6 months or so.

Solara350

Don't trust internet sometimes bro, 300 and 350 has exactly same Engine 350 HP remained the same the 300 has been re-tuned ECU to reduce HP, Lexus got rid of 2.5 Engine which don't have Port D.i.E, They acknowledge that most of Lexus drivers dont like to Maintenance therefore Carbon Buildup thus they started the 200T Engine 5 years ago and released in 2016.

I hope they will make 3.5L IS350 Turbo lol

arentz07

IS 350t?

However in all seriousness, if they put the engine from the LS 500 in the IS, it'd be pretty quick, as in, low 4-second range quick I'd guess. I think it could handle the power too with some slight handling upgrades.