I got a 2014 IS 250 as a loaner from the dealership while I wait for mine to come in - yay Lexus!


So I was playing around with the different modes since I didn't test out Eco mode at all during my test drive. I am actually finding it kind of useful.

First entering the streets or freeway - Sport Mode
Normal traffic but no room to speed - Normal Mode
Getting stuck in thick traffic - Eco Mode
Simply cruising and being a good boy on the freeway - Eco Mode
Getting behind a slow person and then they move out of the way - Normal or Sport
Going up a steep incline - Normal ...or Sport
Twisting road - Sporrrt


All this changing on the fly though did make me wonder if it is bad for the car. In fact, when I was driving home from dinner and other activities tonight and doing this variable mode switching the car got stuck in a lower gear and rev'd high (4k range) for a good 5-7s until I let off the gas pedal and hit it again. This reminded me of the test drive I had with the 335i and one of the primary worries I had with the 335i, except with the 335i it was consistent. This was a one time occurrence with the IS. Granted this is a loaner car with 7k miles on it already so it definitely has some joyride miles on it. Hard to tell if this behavior was because I was switching modes on the transmission too much or if its because this car was horse beaten. Outside of this fluke occurrence the car is silky smooth though so it leads me to believe that it just might not like me switching the driving mode so much.

Thoughts? Anyone else switch modes frequently? If so, have you noticed any bad effects from doing so?


Really curious because ECO mode is actually kinda handy for thick traffic as it allows for smooth sailing with me barely having to touch the brake pedal. Staying in Sport mode during thick traffics gives me a itchy trigger foot making me always gun it when the lane opens up. Not to mention... I'm sure the people in front of me probably don't like seeing the car behind them lurch at them all the time, ha ha hah.

 

I switch modes frequently for similar situations you outlines. In Sport mode, the gears will hold on longer so it's normal for a few seconds to stayed revved in that gear after spirited driving, decelerating.

 

The car also has G sensor so if you're making a tight turn it will hold gear longer. This applies to normal or sports mode.

 

The more I drive my car, the more I find myself using Sport mode more often, and subsequently getting worser mpg. I'll use the ECO/normal mode once I'm at a comfortable cruising speed on the freeway, no traffic, or when no quick lane changes are required.

At stop lights, when the green lights come on, I find myself using either Sport or Sport+ modes since the car feels somewhat of a turtle. I've noticed people have been racing me at stop lights too. Like, wth, are you trying to prove you're faster than me? Lol.

 

True, but only on the 350 with the 8 speed.

 

In order to maximize fuel economy Eco mode is best utilized during city/stop and go driving. At steady state driving like on the freeway with no traffic there won't be a difference between Eco and normal driving modes.

 

I switch modes frequently (usually between Sport and Sport+) with no ill effects.

 

I disagree. I do a lot of highway driving and there is a noticeable difference in mpg between normal/sport modes and Eco mode. I still do most of my driving in sport or sport+ mode though.

 

Try this: drive 60mph on normal then switch to Eco. Do you notice the rpm's dropping? I don't. Eco mode isn't overdrive, it just slows the throttle response which is why people describe it as "sluggish". This only saves gas during acceleration.

 

it also runs the AC compressor less often and limits the fan speed to medium setting.

 

ECO mode, for me, is most useful in heavy, stop and go traffic. It definitely keeps things smooth since the throttle response is so subdued. I don't normally use it in highway traffic, though, since it makes passing more difficult.

Most of the time, I'll keep it in normal mode, but more and more these days I'm putting it into sport since it's just so much more fun. MPG has been taking a hit, but eh, who cares!

 

Thanks for the responses, it is great to see others are switching modes on the fly too!

When the transmission got "stuck" in a lower gear it was right after switching to Sport mode to take the off ramp (slight turn off and uphill) so that seems to match corradoMR2 and dojoman's response.


Not sure it is proof that ECO mode saves fuel in normal freeway driving but I was able to go up a whole 0.1pt in fuel economy (6ish miles) according to the onboard gauges!!! That 0.1 will allow me to go from a Medium drink to a Large drink next time I'm at the movie theater, SCOOOOOOOOOOOOOORE!

 

Same, the first weeks I had my car in heavy traffic I was using Eco mode but found it harder to quickly ditch a lane. Now I use normal mode for traffic, and in winter you don't need Eco mode when cruising the freeway, no one turns on the A/C.

 

last night i got 31 mpg on my way to denver using eco mode

 

Forget about using Eco stick with normal. I tested out on my car to see how many mpg I can gain by driving the whole tank with Eco mode only and turns out I only got 2 miles extra on tank's range compared with normal. Definitely not worth the hassle by keep switching modes during traffic. I have 350, not sure I can speak the same for 250.