Hey guys, I'm new to this forum and somewhat a new owner of a 2013 GS350 F Sport (RWD). I love cars but honestly don't know too much when it comes to the mechanical side of it. Ever since I've had the car (almost been a year now), I feel like the "drive" has been really inconsistent. Sometimes, it's super smooth with no problems whatsoever. Then, periodically, it'll feel "laggy". Obviously since I drive it everyday, I'm able to distinguish how it should really drive and when it's not exactly driving normal. I've taken it to my dealership once for this and the service manager explained how much of an effect the gas I put in my car has on the performance (I always put in 93 Octane) but other than that, he really had no other explanation. Any answers/suggestions on what I can do to fix this would be greatly appreciated. Thanks guys.

 

When i had my previous GS, i had all sorts of responsiveness problems due to a myriad of things as the car aged. Whats the mileage? Without knowing the mileage but from a mechanical perspective: Did they check the air filter, intake, fuel filter or fuel pump? Cleaning the throttle body and then checking the MAF sensor would be a good start and even Oxygen sensors. More far fetched but checking the some exhaust components (pipes, mufflers, catalytic converters) to see if they have any issues.

I've noticed that the GS learns your typical driving style and adapts responsiveness. I realized this when my battery died. The old battery was out for an hour while the new battery was delivered to my mechanic's shop. When the new battery was put in, the car felt super responsive in "Normal" mode. After about a week or two of driving around town, it felt less responsive as I drive in stop in go traffic quite a bit and the ECU "learned." One simple trick would be to disconnect your battery and see if when its reconnected, your throttle response is improved.

The last thing i'd suggest is to possibly ask to test drive a similar car (or two) that may be at your dealership to see if there is a clear difference (RWD may be harder to come by here in the Northeast though).

 

How many miles do you have? You may want to try a fuel system cleaner, Redline is very good. Many cars learn driving styles so if you drive pretty conservatively for a while it may affect response. Normally if there is a issue it would happen all the time, not off and on. Are you carrying any extra weight at times, passengers add hundreds of pounds, tire inflation can affect how a car drives. Spark plugs could effect the way the engine runs but it normally starts idling rough when they need to be changed, could also be a dirty MAF sensor, dirty air filter, throttle body may need to be cleaned, any number of things. Gas does have a effect, try getting gas at the same place and see what the results are. You may want to just try resetting things by unhooking the battery.

 

For what it's worth: that line about gas is nonsense as long as you meet the octane requirements.
Gasoline is blended to exacting regulatory standards, ridiculously consistent across stations and producers.
Our engines require 91 due to their compression characteristics. Nothing more will make a difference, except to your wallet.

 

I would think the only possibility with the gas comment is "bad gas." If rain water is seeping into the underground gas tanks/pumps that might cause a problem if you get a bad mixture (engine pinging/seizing/jerking, poor acceleration). If you consistently get gas from the same gas stations, you usually know if you got some "bad gas."