Cylinder deactivation and start-stop. How much stress is this putting on the engine long-term? And is it worth going from 19/28 to 21/30?

it actually gets better than that! I had a 2008 and 2012 Z06 with 7.0L V8 and I got 30 mpg pretty consistently on the highway and about 18 in town.
why? because in 6th gear on the highway at 75 mph the tach shows about 1300 RPM pushing a car that weights 3265 Lbs with a aerodynamic drag not much more than a motorcycle!

a corvette sits maybe 4 feet high off the ground at the roof line.

I hear a GM engineer say that a corvette uses approximately 12 hp to maintain highway speed. I don't know if that was accurate but considering the TQ they make at low rpm and the fact the overdrive is so high it may be possible.

with that said the new C7 is supposed to be more fuel efficient than the C6 I had. with DI and cylinder deactivation I don't doubt for a minute the new vette could easily get 33 high mpg

I'm averaging about 23 mpg with a, I'd say, 65% hwy and 35% city. By no means I'm driving slowly like grandma but I'm also not beating the hell out of it all the time. This is mostly on ECO mode with a few Sport+ here and there. I got about 350 miles out of my last tank.

That's exactly what I would like to know. I'm guessing they're using the gauge not calculating it.


I would like to see more people stating how many miles they are getting out of each tank. It's pretty obvious how close the gauge is just going from that. When my car was getting 16-18mpg on the East Coast I was only getting around 220 miles. When I moved here I started getting 350-380 miles per tank, and that's driving it like I stole it.

I think humid climates in addition to constant stop and go driving are the biggest reasons for these horrible numbers.

If you want great gas mileage, the Prius is king of the hill, but there are significant trade offs such as looks, power, engine and cabin noise, interior quality, image, etc. Owning a Luxury car with power, solid construction, comfortable seats, noise insulation and many other features that add weight, results in a loss of fuel mileage. Hybrids are really nice, so if Lexus offered the IS300h in the US, I would have that car in my garage next to our ES300h.

My MPG has dropped over 2 MPG in the winter at 22.5. In my 335xi, city driving was around 14 MPG. Now, BMW is using start/stop technology to up their fuel mileage numbers, but that seems to be counter intuitive to owning a sports oriented car. My guess is that the IS350 would beat a 335i off the line unless the start/stop feature was disabled on the Beemer.

I have almost 8K on my 350 F sport. I average about 21-24 MPG. 24 if I drive more highway. My driving is about 50/50 street/highway.

i agree with Bass Mech...my C6 corvette with a CAM and exhaust gets better MPG than the 350 F sport, how embarassing, so i have to use the ECO mode when cruising around DD to stay in the low 20s MPG

I'm at just under 3k miles, and my last tank average was 21 mpg (a new high for me!)

I'm usually keeping it 80% normal, 18% sport, 2% eco-pro. 70/30 highway/city split, but even on the highway I do hit a lot of traffic.

I'm getting 17.5 mpg on on 1,500 mile so far mostly highway in Eco mode.

After 3000 miles I'm getting the following ranges (by tracking exactly how much fuel I use not the car's display):

City/CommuteTraffic 17.8-21.1mpg
All highway 24-26.5mpg

Overall:
3174 miles, 145.97 gallons, 21.74 mpg.

Mostly ECO mode driving, sport+ for fwy merging, cloverleafs or any other time I want to blast away from a stoplight.

According to the computer, I got 15.7 L/100 km (15 mpg) on my first tank of gas. It was 90% city driving in the winter, with a mix of driving modes (50% normal, 25% snow, and 25% sport)

Yea, I own the club for worst MPG here. Ive had mine since July 1st and average of 11.5 MPG, its like 85% heavy city but still.. compared to my 2008 IS350 with same engine, I was getting like 17-18 MPG with same route. Nobody knows why... Dealer says its normal and everything checks out in my car

I recently had an '14 IS350 F-Sport a full day, brand new one and not a loaner. I got to beat on it a little and drive it like I usually drive, I'll was a bit shock reading the computer MPG i was Averaging.. It said 8.6 mpg City.. Thats worse than both of my V8's getting about double that driving hard.. The gearing on the F-sport holds the rev at 4000-5000K if you drive it hard, and doesn't shift into higher gears, this is what I experience and think this is why its averaging so low..

The gearing holds that high only if you have in sport plus mode.

Pickup my car tonight and during my drive home I was getting 27.2MPG using Normal (but I saw the ECO light on the left go on) with outside temperature being 23 degrees! I was also using the adaptive cruise control. If this is what I can expect to see for my commutes than I'm very happy!

Sorry for the fuzzy picture.

http://farm8.staticflickr.com/7426/1...a390f4d6_z.jpg