Hello guys,
I've owned my car for about a year now and I'm getting it moving with some upgrades slowly however I ave some questions regarding maintenance etc.

Oil Question.
So m278 engine. My dealer has put 5w30 229.5 in my car, I'm in UK and I'm quite mad, because it's literally impossible to get 5w30 229.5 here, all of them are 229.51(low saps)
So I'm wondering is it better to ask for 5w40 or 0w40 in the next oil change? since it's available in 229.5 almost everywhere unlike 5w30 229.5. It is a weekend joy car and i drive it hard, so it does go through a bit of oil ( about half bottle every 3 month).

IAT question (during summer)
So I've noticed that IAT must go up during summer especially when idling on red lights. I haven't measured it with any kind of Obd module/app but i can definitely feel it. So my question is what's the best way to combat this? I have found 2 options : VRP meth/blow off valve kit or killer chiller. The latter doesn't seem like a very civilised options as I've heard that cabin temp goes up?

Brakes:
Just not enough stopping power, mine doesn't have a tune however Dyno'd 450hp , running brembo pads and rotors and they aren't good. Has anyone tried any rotor/pad options that improve braking?

Suspension
Yes mine has an airmatic which is great but lately i'm noticing that it's not stiff enough since the car switched from being daily to weekend toy. I've read that lowering module somewhat improves roll and holds car better in turns, however is there anything that can be done apart from spring conversion?

Also how long does your car take to settle down on cold starts? mine takes about 3 minutes to drop to 600 rpm, wondering if that's okay on this engine.

Sorry to come in with so many questions

Here is the panther her self:
So far the only mod is the exhuast, a pretty rare 1 of 5 Miltek valved exhausts that was made for cls63.

 

I can't answer any of your questions but I am impressed with your knowledge and commitment to getting the best performance possible out of this wonderful automobile. It just goes to show you how diverse owners of this car can be. I am at the other end of the spectrum. I get in this beautiful car every day and marvel at the style and overall looks. I wash it every week and frankly, treat it like a baby. I run it fast in sport mode every so often on these winding, country roads where I live and I am always impressed with the performance. It is a 2017 CLS550 and that big V8 twin turbo is all this old man can handle and I shudder to think what a tune or AMG would be like.

When maintenance is required I bring it to the dealer, let him worry about the oil needed and drive out when he is done. I seldom even look under the hood until the next service. I know nothing about the brakes, air-matic or anything else you mentioned so I don't worry about those things as long as the ride is comfortable and stops the car when I want it to stop. The exhaust you say? Well, I suppose I would like a little more growl but I'm almost deaf anyway so things like that would not do me much good.

Every time I get in I enjoy this car immensely. I'm not sure I would enjoy it as much if I was a technically oriented and demanding as you appear to be. Again, I commend you for your enthusiasm to make the car behave exactly as you want it to and maybe I would too if I were 50 years younger!!

 

haha absolutely, thanks but i myself don't know too much either
I love the car ofcourse and it's great for daily use, However when it's sole purpose becomes - fun weekend drives you start disregarding comfort.
and quite honestly dealer, here in UK, at least the once i go to isn't doing too great of a job, hence i try to do all the research myself

 

You can mix 229.51 with 229.5 in a pinch, but the it's best to leave it to the diesels. In the states, dealers mostly use 5W-40 229.5, in the special Mercedes formula. I get it from Amazon, but dealers sell it in quarts here.

Do they not stock a 229.5 at the parts counters? But any 229.5 or 229.51 can be used for topping up with no worries.

 

yes thanks,
I read like 304122397932 posts and discussions about it and found that i can top up with 229.51, which i did, However next oil change I will go for 5w40 229.5 so i don't have to mix 229.5 and 229.51 in the future.
And I just don't have time to go to mercedes, since their parts/service departments are closed on weekends.