It's actually the Direct Injection you're hearing.
All cars with DI have that sound - some have more sound insulation.
Open the hood of a 450 and you hear it as well.

 

I’m aware of that. It’s just that the C300 is louder than any car I have had. I’ve gotten used to it.

 

The new generation C300 is improved then. I thought it was surprisingly quiet.

 

Ya the M254 engine is much quieter than the M264 (from what I heard from owners).

 

My 2017 C is noisy like all of you know. That's why I'm waiting for th2 2025/26 C-EV to try out.

 

In late 2020 I test drove a 2021 gle 350; I liked it OK; however, the car would shake when the engine came back on at stoplights, and I didn’t like having to rev the engine to get up to highway speeds. So, I bought a 2021 GLE 450 and have been happy ever since. The stop/start feature is so smooth I have to look at the tachometer to figure out if the engine is on or off, and getting up to highway speeds is strong and smooth without any drama.

Later on, I experienced the same 350 engine shake on a loaner, which helped galvanize my decision to buy the 450.

When my salesman tried to get me into a 2024 GLE 450e, I told him “No Thanks” (I didn’t even test drive it), because I didn't like the 350 engine, the spare tire had to be deleted to make room for the massive battery under the cargo floor, and, at the time, the 450e was going through “teething” issues -- in fact, I couldn’t even test drive their only 450e because it was “down” for more than a month waiting for that massive battery to be replaced.

As the end of my warranty nears (Nov ’24) I have to decide whether to keep the 450 another 3 years (with an extended warranty) or order a 2025 GLE 580.

 

Well, that shake is gone for the 2024 GLE as it gets its facelift, the 350 also gets the 48V mild hybrid now.

 

So, an inline 6 is smoother than a V8? I turned to Wikipedia for the answer and found this (see link below), but my old brain got tired. There’s probably a reason why I didn’t score as well on the Mechanical portion of the ASVAB 51 years ago. Fortunately that kept me out of aircraft maintenance on a flightline in Montana.

https://en.wikipedia.org/wiki/Engine...herent_balance

 

I thought the same thing until I was told the battery will always keep a reserve to prevent the car from just driving on the 4 banger without electric assist.

 

People say that but I have never found that to actually be true

 

My straight six Mercedes and straight six BMWs were smoother than the BMW V8 and Jeep V8s I have owned. I've never had a Mercedes V8. I think the BMW straight six is one of the smoothest engines made. Both the V8 and straight six are far superior to the 4 cylinder.

 

Although I generally agree that V8 is smoother than a V6, from experience, an inline 6 is smoother than a V8 although others also said otherwise, that said, a V12 is smoother than them all from my experience (not my car but had an opportunity to drive a S 650 at some point it is was certainly smoother than a S 560 at the time. Which I wouldn't be surprised because there are reasons ultra luxury cars like Rolls have 12 cylinders.

 

I just have never found I-6 to feel smoother than a V8 in the same car. For instance the S Class, driving both back to back the V8 is much smoother and more refined than the I6 S500. Same is true in the 7 Series, the V8 is smoother and more refined than the B58 in that car and the X7 driving them back to back.

 

So you're saying the 2024/2025 GLE 350 or 450 come with a spare tire? If so that would be great. If so, when ordering the vehcile, can you opt for regular tires (not run flat)?

 

They come with a spare tire if you don't order the third row seating. My 2024 GLE450 came with non run flat Michelin tires (20" Primacy Tour A/S)

 

I asked my Service advisor about the direct injection carbon fouling on the intakes. He sez it not an issue as long as you use the prescribed octane of fuel 91 minimum. if you cheat and use lower than that is what loading up the EGR valve and intakes on the head. Some of that sound is the fuel injector too.

 

@HDLBRG Thanks for that link. Interesting read. Passed it on to my math major family member, who is also an F1 fanatic. I expect she'll love it!

 

@PeteInGilroy Recommend you consult the Dealer Order Guide for wheel/tire mobility by model.