I'm wondering what MPG figures you guys are getting with your new 3IS. It would be interesting to note if its any better than the previous gen.
State City/Highway as a percentage.- how much do you drive on the highways and how much just local roads to the best of your knowledge as a percentage figure.
I'm been getting pretty terrible mileage - worse than i expected - but wondering if its because the engine is so new. I've been averaging about 19-20mpg, and 80% of my driving is on the highway at highway speed. I have the 350 RWD and less than 300 total miles so far. I also have not been driving the engine really hard since its new and in the break-in period, so I really would have expected a little better. Also, my trips are short as my commute is only 10 miles each way, so maybe that factors a little bit into it as well. I definitely plan to keep an eye on it tho.
You're not going to get the projected mpg that Lexus projects that early on. You will likely need a healthy 1,000 miles until the engine is fully "broken in". Then there is the fact that the computer will be adjusting to your personal driving habits to be more efficient. By the first 3,000 miles you should have a good dataset to average.
You're not going to get fair numbers until people have gotten through the break in period -- because one is not supposed to keep it at the same rpm -- thereby limiting the best way to get reliable mileage numbers.