My shock is manifasted by looking at vehicles across many markets and making a broad comparison (i.e. looking outside of just 4 door luxury sports sedan).

2014 Lexus IS350 F-Sport RWD - 6 cylinder, 3.5 Liter, 306/277 TQ, Curb weight 3,593lb, , 19 City - 28 Hwy.

2014 Chevy Corvette (C7) LT1 - 8 cylinder, 6.2 Liter, 455 HP/460 TQ, Curb weight 3,298lb, 17 City - 29 Hwy

The C7 is roughly 300 lbs lighter, BUT it's also 2 cylinders more and the engine is also 2.7 liters larger. This leads to the C7 producing 149 more horsepower and putting down 190 ft lbs of more torque with roughly the same (or better) real world MPG numbers as the IS350.

I have bolded in above what's most important. I am a huge fan of efficient engines and it's sad that with such a great car (in so many others ways), Lexus has it coupled with an outdated and inefficient engine.

I know it's not fair to compare a luxury sedan with a sports couple, but I was primarily looking at just specs and the numbers don't lie. I hope this provides you with a clearer picture for shock value purposes. :thumbup:

~ Im2bz2p345 :)

P.S. - You can also read my suggestion on how Lexus could totally rape the 4 door sedan market here: https://www.clublexus.com/forums/is-...ml#post8246341

C7 corvette has a cylinder deactivation feature while cruising at highway speed. This way it achieves great 29 hwy mpg. Now if you drive aggressively on C7, it is a very hungry engine and it will consume a lot more than 3IS 350 (assuming also being aggressive).

I agree, however, that the engine is outdated and Lexus must catch up with the competition.

just wanted to give a brief update..my first few pumps i was babying the car, breaking it in and driving 99% eco mode. was getting between 19-20 mpg. this evening at roughly 1200 miles, i pumped again and recorded a new high of 22.5 mpg with 30% eco mode, 65% normal mode, and 5% sport+ (couple fast runs here and there) since my last pump.

i started switching over to driving in normal mode mostly in the city and suburban areas because another CL member made a very logical point. in eco mode, when you need to accelerate like going uphill because the response is so delayed, you step on the pedal harder, burning more fuel, so in essence you're overcompensating. with that logic i switch to normal mode, still with good discipline on my feet to not accelerate hard or quick, and with the quicker responses and quicker gear upshifts, i am able to get going faster without having to overcompensate and mash the pedal. i still driving eco while i'm on the hw and i'm sure thats played a small but helpful factor to the higher mpgs.

LOL, don't get all excited about 22.5 MPG! :rolleyes:

One thing I noticed is if you are idling a lot with this car it really sucks up gas. I had to wait in the car wash lane last Friday after just filling up and reset, my MPG was under 15 MPG for few days. Just today it made it back above 20 MPG. I still have 3/4 of the tank left so I'm hoping I can get it closer to 25MPG by the time it's almost empty.

Since I installed the Takada intake (about 3 months ago), i've been averaging 20-21 MPGs with about 50%/50% highway city driving. Just had the f-sport exhaust installed last weekend, and current tank is close to 22MPGs (and this is with a few hits on the gas to listen to the new exhaust). Going to see how the next few tanks go to see if any difference really is happening. Odo currently sitting about 6400 miles.

Do you feel any gain in a power department after both intake and exhaust? Even if a little gain but if noticeable then it is good.

With the two combined, not really. But then again i don't consider myself good enough to know the difference if there is one. When the strip opens back up gonna take her for another run and compare her to my times from last november (all 4 runs were 13.9-- to 14.01- at 100mph give or take 1 mph)

Anyone come across any problems with 3IS fuel injectors and / or spark plugs?

Could either / or be the culprit?

Thanks.

Yea I'm still breaking in my engine and on my first tank of gas and I'm gettin 18MPG average. I'm driving like 90% of the time on normal mode too....

21.4 mpg mostly city driving, but not stop and go. Same mpg so far as the 2IS

temperatures went up 30 degrees today and I started driving only on sport mode from normal mode...my MPG went up 2 MPG from 18...still not sure whether it is the temperature or the mode...many on the forums said the 2IS' gets better gas mileage driving on power mode...any thoughts?

Been discussing this very thing in this thread.

I'm just weighting in here...

I'm getting 11-13 MPG / 18-21L/100KM (80% City / 20% HWY). ~4000 KM on the Odometer. Accelerating slower than usual from zero, and driving the speed limit :) in other words, driving like a complete troll.

I rarely use Sport+ mode now, as when I do, if only giving it for a couple seconds, my fuel gauge goes down 1/8 of a graduation.

I've been driving it since November 2013 in cold weather. Now the weather is getting better, 1+ degrees; I'll see if it improves. I've asked the dealership about this a few weeks ago and they're saying its from the cold weather. I think there is something inherently wrong with the car (maybe my car in particular). I'll know once it goes in for its second servicing at 8000KMs.

Right there with you, as I've had the same exact problem since new.

BS, as I chose the car to better my fuel economy.

Please keep us posted. :|

Are you frequently driving in heavy, stop and go traffic? I've had a few commutes where that was the case and I was around 18L/100km. For the most part I drive in suburban traffic with stops, but not close to stop and go, and in that I've been getting 13-14L/100km during the coldest days. All situations included, of which 20% is highway driving, I've been between 12-13L/100km this winter. Before it was really cold, I was getting 11-12.

Unless you're continuously hitting stop & go traffic, or pushing it hard, there's no way a healthy version of this engine should be getting such dismal fuel economy.