Two weeks ago, I purchased a pre owned/certified 2014 GS 350 F Sport and about a week later my parents purchased a pre owned/certified 2014 GS 350. When driving the GS 350 in normal mode, my parents, my son, and I find the acceleration to be slower than that of my F Sport (also driven in normal mode). When we asked the dealer about the different feel of acceleration, they insist that the acceleration should be the same as the engines are identical. Has anyone experienced the same issue? The acceleration in the GS 350 in normal mode feels like acceleration in my F Sport in Eco mode.

Thanks in advance for your feedback.

 

The engines are exactly the same so throttle response in normal mode in an F-Sport will be same as the throttle response in a non F-Sport in normal mode.

There are a few reasons why that could be the case but i'd have the dealer check to ensure your parent's car's computer is properly switching between the modes. It doesn't seem likely, but its possible the car is consistently in Eco mode even when you push down to put it in "Normal" or toggle it right to "Sport" mode in your parents non-F sport.

I'd also have the dealer potentially clean out the throttle body and ensure you are using the highest octane fuel possible.

 

Thanks, AJLex19!

 

Probably the first thing I'd check is that you're running premium fuel in both cars. The engine will protect itself (costing power) with lower octane fuel.

For anything else, I would recommend doing an instrumented or controlled test, as butt-dynos are notoriously unreliable. When I drove an F-sport I felt it was faster, too, but in reality it was just having "sport" in the name and me driving it harder.

Disclaimer, the following statement likely refers to urban legend, rumor, or misinformation. I had long-ago been told that Lexus cars (attributed to VVT-i, whether correctly or not) had a hysteresis that would adapt to your style, either optimizing for power or fuel economy. Repeat, not sure this is actually true.

 

Thanks spoogenet. Until your response, I thought a possible explanation for the acceleration issue could have been that the car was adjusting to the previous owners driving style!

 

Yes driving style plays a big part. My '15 GS non F Sport can be freakishly fast or not very responsive depending on my driving style. Of course shifts will be rougher when it senses you like immediate power delivery.