home4ya

Hi, new here and just bought a black FSport 2014 IS250 with 39K miles. My friend has 1 and when he drove mine he mentioned mine seems a bit gutless, esp first gear, compared to his, is it his imagination or are there any fuel injector issues I should have done/looked at or additives to add to the gas tank? Any help would be appreciative. BTW - when I bought it, there was a lot of I'm guessing "carbon build up on both exahst, I actually thought it was an oil leak, does that mean the previous owner used cheap gas and I need to clean or fix something? It's a total dog from a stop, it even feels like a long delay. Is a tune up and or a certain type of cleaning needed per your experience, esp with the carbon build up I saw? THX!!! (my sons olf Honda accord is quicker off the line than me)

HOMER350

Look up KCLV in this thread (knock correction learning variable...I think). Depending on how the car is driven, the ECU will adapt and well...be faster if you drive the car faster. But there's a little more to it than that, I'm still figuring it out.

I'm not sure about the 250 fuel injection you may have greater need to clean than the 350.

E46CT

3IS 250 is a very heavy car with little power to move it around. Even the 350 is slow by modern standards. At 39k miles i can't imagine any maintenance related issues already causing power loss. those things don't normally happen until you're deep into the 6 figure territory. I think you just are realizing you bought a very slow car.

arentz07

Well, he also said it felt slow "compared to his [friend's]". I assume his friend also has a 250? If not then yeah. But for most people doing 0-60 in the upper 7-second range isn't too bad. For what this car is? Maybe. But I think he was asking why it might be slow compared to other 250s.

E46CT

Unless it's timed or raced side by side, "feeling" is just conjecture.

arentz07

Yeah, but there are legitimate cases where kclv, carbon build up, or other factors, such as fuel, could cause the car to respond differently... I prefer to just be helpful myself.

E46CT

I like to base what I say on facts. All we have to go on here is what's been provided: a friend saying it feels slow and OP saying the car he just bought feels slow, probably at least partially influenced by what his friend said. What we do know as fact is the IS250 is slow. So the most likely explanation on a 39,000 mile car is that it's just a slow car and there's nothing wrong with it.

Yes he should maintain it well, but I wouldn't be sending him on any wild goose chases just yet absent any particular evidence he has a problem.

arentz07

Right. However I feel there's no need in saying it is "very slow". It's an IS 250. There are much slower cars. Mid 7-second range 0-60 is perfectly acceptable. All of my previous cars before my IS 300 were slower than an IS 250 at least on paper, but I'd never say they felt like a "dog" as the OP said... maybe except my Buick, which had really tall gearing, only 175 horsepower, and weighed 3300 lbs. Granted I haven't driven a 250.

There are some other possible explanations too, like the electronically-controlled throttle lag. This is commonly remedied by using something like the Apexi throttle controller. Maybe it's just that? For a while I wondered if something was wrong with my car, but then sure enough, the delay is just a part of the 3IS experience unless you mod it out. Something to look for anyway.

home4ya

Thanks for the replies. I expected to perform "much quicker off the line" than the 4Runner I sold with 180k miles to get this. After a few days, it just seemed "delayed" from a dead stop and then I recalled cleaning all the carbon off the 2 exahust and wondered if asking you all (the experts) if a fancy "STP treatment" or such might help? My friend also has 250 and he agreed after driving mine seems a bit sluggish from a dead stop compared to his. Just seeing if any advise oe similar experiences? It only has 39K but I am concerned original owner may have used cheap gas causing carbon build up I saw and if possible, is there an easy fix? THANK YOU!!

arruda89

I had a 250 F sport, AWD, my friend had a 250 RWD, and let me tell you, that made a huge difference in performance. The AWD was slow af, my friends RWD was a lot quicker, especially off the line.

So do you have an AWD? It does add about 400lbs? to the car.

home4ya

I have the 250 RWD FSport

EZZ

The 350 is comparable in speed to a 328 (and faster at freeway speeds) and still cheaper with better handling. Its fine for what it competing against. If Lexus adds in the V6TT, it will have a competitor to the 340.

I agree that the 250 was very slow so they made the 200t to help it to better compete against the 320.

dizlex

OK, I'm not impartial, because I have an IS350, but it is not "slow by modern standards". It's faster than most cars. Of course, the turbocharged 6-cylinders are faster.