Festertester

For 2019 G63 22” OEM wheels/tires, what tire pressures are you all running? I have 36(F)/48(R)

pdeacon

I'd check the recommendations on the inside of the gas filler door. 48 lbs. rear sounds high to me. On my MY '16 I ran 38 lbs all around and it worked well with the old suspension set up.

places

I'm running 42 all around on my 2018.

Festertester

Yes 48 rear was per instructions in door / fuel filler sticker but it feels a bit jumpy over bumps

CUZCO

The way I understand the tire pressure is no matter what diameter tire you have 20, 21 or 22" if loaded to the max (5 people and luggage) The front is 38 psi and the rear is 49 psi. however if carrying a lighter load (3 people and luggage) then the front is 38 psi and the rear is 35 psi.

I am running mine at 38 psi all around but I never have 5 with luggage.

Bob Z.

iTrader: (1)

So I put the new G63 tires on my 2020 G550 today - look great, but the shop was surprised to see the recommendations of 38 front and 49 rear - is 38/38 still recommended? It is just me and my wife and we do not carry anything heavy (nor are we heavy).

places

I run 42 all around on my 18.

pdeacon

I run 38 all around on my '20 G550. Works great. No heavy loads and mostly two on board.

Festertester

Yes I’m running 35-38 f-r now. It’s compliant and planted

Bob Z.

iTrader: (1)

The recommended tire pressures on the placards for the G550 & G63 are different...lower pressures on the G550 with 20" tires as compared to the 22" tires on the G63; however, both have higher rear pressures. I always thought the axle that had more weight over it, such as the one with the engine, had higher pressures - first time I have seen it the opposite.

carlosamg50

Hi guys

Reviving this subject, the placard on my 350d says 32 all around for lighter load. 3 people which seems way off what you guys talk about, is thar because you all have the V8’s?

Im about to fit OEM 21” G63 rims and tyres to fill the arches a little more, my placard doesnt change for the increased wheel size, its still 32 all round.

Do others inflate based on preference or the placard on the fuel flap?

Thanks
Carl

streborx

My G550 says 35 (F) and 44 (R) on the B-pillar door frame for the 275/50R20 OE tires (Pirelli Scorpion Zero A/S) and 1014 lbs maximum weight (passengers + cargo). The fuel flap says 32 (F&R) for 3 passengers + cargo, and 35 (F) / 44 (R) for 5 passengers + cargo (max weight). No weight is specified, but I assume 3 passengers + cargo is 60% of max weight, or 608 lbs. I drive alone 75% of the time (~ 200 lbs), and can't recall ever having a three or more passengers.

The Pirelli's are rated 113 load index and V speed (149 mph), and the sidewall is marked "max 2535 lbs at 50 psi max". I currently have a set of Yokohama Geolander 275/55R20's mounted, which are rated 117 load index and H speed (130 mph), and the sidewall is marked "max 2833 lbs at 50 psi max". This means I can accommodate the maximum 1014 lbs weight at slightly lower pressures than 35 (F) and 44 (R), but I maintain these pressures (rather than 32 psi) because fuel economy is better (I average about 19 mpg), and the ride is not objectionably harsh (a benefit of not running low profile tires on 22" wheels). I have about 17K miles on the Yoko's and am not experiencing any accelerated or uneven treadwear characteristic of over-inflated tires.

My understanding is that inflating the tires to 32 psi and loading the vehicle to max weight is far more problematic than keeping the tires inflated assuming max weight, hence the door pillar placard specs 35 and 44 psi.

Regarding your new 21" tires, pay attention to the load index. If it's lower than the OE tires that you're keeping at 32 psi, you'll want to run a higher pressure. Also, if you haul a trailer, the loaded trailer's tongue weight needs to be factored in as part of the the 1014 lb. max weight.