I understand you on that. But those two cars are simply very different animals.
Whatever, if you would buy the CLA, they have a very bad reliability reputation. If you search the internet, you will find anormally more warnings about those cars. Maybe they had a rough start and corrected it afterwards, but I would be very careful not to invest in a money pit.

 

I haven't noticed a throttle lag on my RCF. It puts a smile on my face every time I drive it. The only complaint I have is that I tend to accelerate hard out of a light and then back off quickly. The RCF is programmed to hold the gear for a while in case you get back on it. More so in sport and sport+. The way around that is for me to use the paddles. We looked at the C and E classes before buying the RCF. The quality was impeccable, what I didn't like was the little 4 cylinder and 6 cylinder turbos. I am not anti-turbo, I currently own a Turbo Trans Am which is similar to a Buick Grand National and I bought my first turbo back in '84. Turbos deliver a ton of power, but put major stress on motors that are in boost all the time and they get expensive to maintain once they get some miles on them. Our MINI Cooper S got very expensive once it hit about 50k miles.

 

 

4cyl turbo fun for a week you will regret, but its your choice.

 

Why not go for a 2015 C63 AMG coupe? You can get one for the same price as an RC-F.

 

CLA screams econobox

 

In sport+ and manual mode, there should be zero throttle lag. I use Octane 94 so the fuel also makes a difference since it is a very high compression engine. My other car has a 8 lbs flywheel/cable driven throttle and even that does not have the sharpness of the response my RCF has. In these modes, the throttle response is so brutal that the passenger will hit the head on the head rest, if you don't make the passenger aware that you will suddenly stab the throttle.

The throttle has e-sensors in it and it measures how you roll into the throttle. If you gently roll into the throttle, it will ease the opening of the throttle body while it will suddenly open it if you stab it. Also, the throttle response is dialed back in normal and ECO mode especially with auto mode. For some people who want more, it is easily made even more sharper by slight mod of Apexi throttle controller.

Having said that, you said you live 6000 feet above sea level in Colarado. CLA45 AMG is a M235 competitor. On sea level, RCF should be significantly quicker both in an acceleration or around the track. However, a turbocharged car like CLA45 AMG would be a better option at very high altitude since turbo cars do not lose as much power at high altitude as FI cars. I would not be surprised if the CLA45 AMG is actually quicker than the RCF at 6000 feet. N/A cars are the worst when it comes to powertrain loss at high altitude.

 

was the RCF warmed up when this lag happened?

 

I notice the throttle lag also. Not so much once you are on it, but from casual to full on lags. Simple solution for me was a throttle controller from Apexi. It wires inline and takes control of the fly by wire input from the pedal. In some cases, it's almost too much. In the red mode from a stop in Sport+ mode, it wants to go right now and tends to be abrupt, not really conducive to city driving. I'm undecided if it has resolved the problem, but have only had 1 week with it and it's not my daily driver. I'm sure once I get used to the pedal feel it will be a good fix for the minor lag issues. I don't think it add HP like a tune, but feels more responsive. I have had the fuel pump update.

 

I didn't even know MB make CLA 45, way to cheapen AMG line of cars. What's next A 45?

 

Lag is kind of general. There is throttle response lag, lag from lack of torque, and there is lag from the trans kicking down a few gears. I'm not sure everyone here is talking about the same thing. In Sport or Sport+ in lower gears or in manual mode, the throttle should be snappy and torque should be ample if you are in the proper RPM range. The low-end torque of the turbo AMG is going to feel way different than the mid-range torque of the naturally aspirated Lexus.

 

Already done lol. I don't really think it cheapens the AMG line, as it's a nice entry into the line. Similar to the RS3. Would I buy any of them, no.

 

There is a GLA 45 AMG also. It's a I4 (4 cylinder engine).

The days I remembered back when ALL AMG's were AT LEAST 8 cylinders. These days are gone.

 

Never noticed any lag in the RCF. I actually think the throttle is more responsive than my CLS550. I rarely drive my car in auto mode, so I don't notice lag in manual mode plue sport or sport+. I have had the apexi on the car for 2 years, so maybe I forgot how stock feels