[Godfather]

Hi everyone, just an observasion ... I am not one who uses the "auto" climate control so it is always on in some way or another, I prefer to simply turn my climate controls on or off using that button. So it has cooled off a bit in North Texas so I have been driving around mainly with AC off. Typically, from the many prior cars Ive had, this results in a bit more performance as the AC can put a little strain on the engine from the compressor being on. My RS400 is noticably less responsive and seems to shift much earlier with the AC off than it does when the AC is on!!! Anyone else notice this? The difference is VERY obvious. I turned the AC on this past weekend and sure enough the car was so much more responsive and aggressive and held gears a bit longer. Is this intentional by Infiniti since they figured most folks would always be using "auto" climate control which from what Ive read on the forums seems to keep the AC compressor on at all times? It is the only car Ive ever had that is reverse of what typically happens when one turns the AC off in a performance car. Anyone?

 

[Bevo]

Haven't noticed and I'm in Houston

 

[DavidDT]

you can turn a/c off without fiddling with main "auto" - go to climate, push a/c twice - it will stay off until you push auto again.

 

[MajDuty]

Is there any way to have fresh air coming in without the fan blowing cold air even on its lowest setting?

What I mean is, even with AC not on, as in it is not pushed and not lit up and not on auto, with the fan at its lowest setting cooled air is pumped in. Turning the fan off no air comes in and it gets too hot. It just seems like the AC is always pumping cooled air into the cabin. Sometimes I just want fresh outside air to come in, not cooled and not heated (without opening the windows) but there doesn't seem to be a setting for that - the air is always artificially heated or cooled

 

[DavidDT]

Is there any way to have fresh air coming in without the fan blowing cold air even on its lowest setting?

What I mean is, even with AC not on, as in it is not pushed and not lit up and not on auto, with the fan at its lowest setting cooled air is pumped in. Turning the fan off no air comes in and it gets too hot. It just seems like the AC is always pumping cooled air into the cabin. Sometimes I just want fresh outside air to come in, not cooled and not heated (without opening the windows) but there doesn't seem to be a setting for that - the air is always artificially heated or cooled

read ^ [above]

 

[MajDuty]

I did. I know how to turn of the AC

 

[MajDuty]

Interesting...so apparently turning "off" the AC isn't enough. You have to turn it off, then back on, then off again...to get it to turn off off. Turning it off doesn't really turn it off it just kind of turns it off, huh? Cooling without the compressor or something running? So when it is on (green light) you must be getting super cooling.

I live where temperatures reach 109F and I've never once had to turn my AC "on"

Sorry for derailing the topic of it affecting performance

 

[Godfather]

This forum is something else. I know how to turn the AC on and off. I do not use "AUTO" climate control. When I push the on or off button it is either ON or OFF lol. Not very difficult. By reading this and many other threads about the AC and auto climate control (here and on the Q50 forum) I'm convinced most people have no idea what their car feels like with the climate control FULLY off.

 

[DavidDT]

you are all correct indeed...

 

[Godfather]

Just wanted to share an update related to this matter. I recently brought the car in for a tire fix and the dealer gave me a 2018 Q50 as a loaner. It was the 300hp version. Departing the dealer to head to work, it was immediately noticeable that throttle response was much sharper and quicker in the loaner than my Q60RS. I am comparing HVAC controls OFF in both cars. The Q50 also had a much more aggressive tone to it, whether piped in and fake or not, it sounded much nicer than my 2017 RS. The throttle response had an immediacy to it and was much more sensitive then my car. Because of this, I had the dealer take a look at my car for any issues. They didn't find any. However, they did a comparison between mine and a Q50RS and their behaviors were the same. The tech and service manager both stated that when the HVAC (AC) is "on" that the ECM changes throttle sensitivity due to the extra load of the AC compressor. Funny and frustrating thing is, the car feels perfect with the AC on, but lazy when off. Nissan got throttle tuning spot on when the AC is on, but failed when it comes to have it fully off. They basically overcompensated for the AC, but it resulted in a fantastic throttle response feeling. Sadly, when AC is fully off, not so much.

I cannot explain though why the Q50 loaner with "lesser" 300hp variant felt so strong and so lively. Clearly they did some tinkering to the tuning on the 2018's and sadly it was more fun to drive then my RS.

Why they do not roll out an ECM update is mind boggling because there is a drastic difference in how each feels and drives. The loaner was hugely responsive to throttle inputs where my car and other RS's tested were/are not. I did test drive another Q60RS (2017) and its behavior was exactly like mine.

The RS is supposed to be the top performing model and it pisses me off that the "lesser" model feels so sporting to drive and my RS feels so lazy. And yes, I am comparing "standard" driving modes in each vehicle.

Support and petition for a software update from Infiniti!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[tomro]

Just wanted to share an update related to this matter. I recently brought the car in for a tire fix and the dealer gave me a 2018 Q50 as a loaner. It was the 300hp version. Departing the dealer to head to work, it was immediately noticeable that throttle response was much sharper and quicker in the loaner than my Q60RS. I am comparing HVAC controls OFF in both cars. The Q50 also had a much more aggressive tone to it, whether piped in and fake or not, it sounded much nicer than my 2017 RS. The throttle response had an immediacy to it and was much more sensitive then my car. Because of this, I had the dealer take a look at my car for any issues. They didn't find any. However, they did a comparison between mine and a Q50RS and their behaviors were the same. The tech and service manager both stated that when the HVAC (AC) is "on" that the ECM changes throttle sensitivity due to the extra load of the AC compressor. Funny and frustrating thing is, the car feels perfect with the AC on, but lazy when off. Nissan got throttle tuning spot on when the AC is on, but failed when it comes to have it fully off. They basically overcompensated for the AC, but it resulted in a fantastic throttle response feeling. Sadly, when AC is fully off, not so much.

I cannot explain though why the Q50 loaner with "lesser" 300hp variant felt so strong and so lively. Clearly they did some tinkering to the tuning on the 2018's and sadly it was more fun to drive then my RS.

Why they do not roll out an ECM update is mind boggling because there is a drastic difference in how each feels and drives. The loaner was hugely responsive to throttle inputs where my car and other RS's tested were/are not. I did test drive another Q60RS (2017) and its behavior was exactly like mine.

The RS is supposed to be the top performing model and it pisses me off that the "lesser" model feels so sporting to drive and my RS feels so lazy. And yes, I am comparing "standard" driving modes in each vehicle.

Support and petition for a software update from Infiniti!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

If this is the case, I'll be the second one signing right under you.

 

[Bevo]

Is there any difference between the two models under full throttle?

 

[testrage]

I guess I take the AC being on for granted. Even on days when I roll down the windows, I simply leave the AC on (dual zone climate is set at 75 deg F in my car). Is there a reason you would not just leave the AC on at all times if the issue is that the car doesn't seem as responsive when the AC is off?

 

[Omenx]

Reviewing the Zero to Sixty webpage and their results, they show basically the same stats so we need more review into the science.

https://www.zeroto60times.com/vehicle-make/infiniti-0-60-mph-times

 

[Godfather]

Is there any difference between the two models under full throttle?

Yes, the Q50 loaner was the 300hp version and at wot it was certainly slower then my RS. The biggest difference was simply cruising around town, starting, stopping, passing folks on the highway, etc. it was extremely dialed in and very lively. I almost thouht it was too agressive for a sedate looking 4 door considering the sporty model should be/is the RS. Its THAT good. During a daily commute, dare I say it was loads more fun than my RS.

Trust me when I say, Im not happy about finding this out and I cannot understand why Infiniti wouldnt perform ECM or TCU updates when the new iterations are that good.

I thought about leaving the HVAC on full time like most do, it will just take an adjustment on my part. Its something that I just never have done with my long line of previuos vehicles.

Something to note about the Q50 loaner was just how immediate the transmission responded to slight throttle inputs. It was hugely different and super responsive compared to my RS with the HVAC off. Sometimes I will need to accelerate to pass a car or whatever and I will feed in some throttle and there is no reaction by the trans. It doesnt downshift, it just lugs along doing nothing. Yet, feed in slightly more throttle and the car jolts forward giving you way more than you asked for. Basically like an on/off switch. Whoever tuned this thing at Infiniti must be an idiot.

 

[Bevo]

Yes, the Q50 loaner was the 300hp version and at wot it was certainly slower then my RS. The biggest difference was simply cruising around town, starting, stopping, passing folks on the highway, etc. it was extremely dialed in and very lively. I almost thouht it was too agressive for a sedate looking 4 door considering the sporty model should be/is the RS. Its THAT good. During a daily commute, dare I say it was loads more fun than my RS.

Trust me when I say, Im not happy about finding this out and I cannot understand why Infiniti wouldnt perform ECM or TCU updates when the new iterations are that good.

I thought about leaving the HVAC on full time like most do, it will just take an adjustment on my part. Its something that I just never have done with my long line of previuos vehicles.

Something to note about the Q50 loaner was just how immediate the transmission responded to slight throttle inputs. It was hugely different and super responsive compared to my RS with the HVAC off. Sometimes I will need to accelerate to pass a car or whatever and I will feed in some throttle and there is no reaction by the trans. It doesnt downshift, it just lugs along doing nothing. Yet, feed in slightly more throttle and the car jolts forward giving you way more than you asked for. Basically like an on/off switch. Whoever tuned this thing at Infiniti must be an idiot.

Maybe standard modes for both models aren't designed to be comparable. See if you're happier cruising in Sport mode. Personally 90% of the time I'm in ECO mode. This coming from a guy that rides a 2017 CBR1000S1 which will blow the doors off of any production car.

 

[Red Sled Q]

Using your AC typically draws more vacuum (higher idle)and higher vac levels advance the timing....which makes a bit more go.

 

[Tony Turbo]

Interesting find. I never have noticed this, I'll have to do some comparisons.

It sounds like you got an answer from Infiniti on being attributed to ecm tuning. The only thing I would have thought was the fact that the fan comes on when you turn the AC on. Maybe some extra cooling over the radiator and HE reduced some heat soak you would otherwise start seeing? Doesn't seem like that would result in the type of behavior you consistely saw though

 

[JonnyB]

Yes, the Q50 loaner was the 300hp version and at wot it was certainly slower then my RS. The biggest difference was simply cruising around town, starting, stopping, passing folks on the highway, etc. it was extremely dialed in and very lively. I almost thouht it was too agressive for a sedate looking 4 door considering the sporty model should be/is the RS. Its THAT good. During a daily commute, dare I say it was loads more fun than my RS.

Trust me when I say, Im not happy about finding this out and I cannot understand why Infiniti wouldnt perform ECM or TCU updates when the new iterations are that good.

I thought about leaving the HVAC on full time like most do, it will just take an adjustment on my part. Its something that I just never have done with my long line of previuos vehicles.

Something to note about the Q50 loaner was just how immediate the transmission responded to slight throttle inputs. It was hugely different and super responsive compared to my RS with the HVAC off. Sometimes I will need to accelerate to pass a car or whatever and I will feed in some throttle and there is no reaction by the trans. It doesnt downshift, it just lugs along doing nothing. Yet, feed in slightly more throttle and the car jolts forward giving you way more than you asked for. Basically like an on/off switch. Whoever tuned this thing at Infiniti must be an idiot.

Perhaps something was off with your car? When I had a regular silver sport or luxe as a loaner i was impressed how much slower it was, didnt know 100hp (even less whp) makes such a difference. The moment I got back on my RS (pre-JB4 or any mods) that difference was huge. Same when I plugged in the JB4 and EWG wires, car started spinning off in 2nd gear on an AWD with Michelins PS 4S - which is insane! Hope ur Q get sorted out soon.

 

[chomachomachoma]

Have you thought about installing the pedal tuner from Burger? I have it on mine it does make a significant difference. You can fine tune your throttle to use a setting for when a/c is on and another for when it's not.