I have a 2022 Ascent Touring with 24,000 miles. I have two big concerns and I haven’t found a clear solution during my searching. I live in the desert Southwest… we have heat and elevation changes (i.e., mountain passes).
1. Hesitation. Similar to this link (2023 Ascent – Hesitation from Dead Stop), my Ascent hesitates substantially when starting from a stop. Although I haven’t tested every possible variable, I believe it has to do with heat and 87 octane. For example, when pulling onto a busy road, depressing the accelerator initially does very little to get the car moving. Then after what seems like a couple of seconds, the car will accelerate normally. My hunch is the intake air temperature is high, thus the car aggressively pulls timing. I do not believe it is a CVT or turbo lag issue. It is really easy to duplicate if you wait in a drive thru at your local 6 bucks and really get the intercooler heat soaked.
My wife is the primary driver of the Ascent and she raised this concern many times as it is truly a safety issue. We always use top tier fuel (e.g., Chevron, Shell) so I asked her to only use 91 octane (the best we have in Arizona). After switching to 91, the issue has gone away. Any time she doesn’t use 91, the hesitation returns.
I mentioned this to my service advisor and not once but twice she recommended I should use 91 because “it has a turbo”. While I am not unfamiliar with the needs of forced induction and high compression (I am quite proficient with fuel injection, mechanical repairs, and I generally wrench on my own cars; I turbocharged my 2003 Miata), their recommendation goes explicitly against the owner’s manual and so many discussions I have read on this forum. The Ascent is designed for 87. In my case, that just isn’t true. And before you say run some fuel injector cleaner… I generally don’t like putting magical additives in my cars. I have always used top tier fuel, and the issue only exists with 87. Hence I do not believe it is a fuel flow issue.
2. Cruise Control. Similar to this link (Cruise control set, slowing down without brake light…), I believe there is a design flaw in the cruise control programming. When cruise is set at highway speeds, the vehicle will lightly drag the brakes (without lighting the brake indicator on the dash) to keep the speed constant during a downhill grade. Sorry, but dragging the brakes going downhill goes against my every driving instinct (note, 2 of my 4 vehicles are manual transmission; I downshift frequently). How do I know it is dragging the brakes? I’m going 75 MPH downhill and the RPMs are basically at idle speeds. The car is keeping speed without engine braking. In fact, you can feel the slight vibration from the brakes dragging. Disable the cruise and the car stops vibrating and coasts smoothly. What I usually do is temporarily disable the cruise and tap the left paddle to downshift into a lower simulated gear.
As a result of the cruise dragging the brakes, we get some brake shudder when stopping from highway speeds. Some people call it “warped rotors” .. we likely have some uneven pad transfer due to the heat generated from the cruise control dragging the brakes down long grades.
Has anyone experienced similar concerns? I have to be honest, the dealer is really frustrating as there is no intent thus far to do additional research. It also seems the folks I have worked with don’t even know the characteristics of the cruise control. And the one-size-fits-all “it has a turbo” reasoning for 91 is just wrong.
Thoughts or suggestions? Thank you for reading.
Matt
