[Enklein]

I passed by a tire shop last night to top off my tires only to find out that I've been running my tires at least 10lbs below the MB recommendation for my tire size. Per the sticker on the door jamb, the recommendation is 44lbs!!

I've had my GLA since Aug '15 and already racked up 7k miles. When I took delivery of the car, I was futzing around the instrument panel and read that I had 32lbs for front tires and 29lbs for the rear tires. Thought nothing of it at that time since I figured everything was to factory specs. I never bothered looking at the sticker either.

Concerned, I spoke to a service adviser this afternoon and was assured that no damage was done to my tires.

Has anyone experienced this? I know we don't get any warranty for the tires, but "if" I run into an issue with the tires down the road and am told it's due to running them low, I want to be able to have an argument.

Anyone?

 

[SSBGLA45]

First what tires and size is on your GLA? Do you have run flats or performance tires? Is it a US spec GLA and the reason I ask is there are many variants of the GLA depending on the country of delivery. With that said I have not heard of any spec for 44 lbs and the norm is 36 lbs (understand the manufacture has to balance ride comfort-performance (as in handling)-mpg performance-tire tread wear so the inflation specs reflect those parameters). Point being is that your tire pressures you noted are fine and do not 'damage' your tires. I do not run my tires at 35 psi but rather at 32 psi…I do not care about mpg performance/tread wear but do care about performance.

You should verify where you are seeing this "44 lbs" spec

 

[zico21]

As I recall, there is a sticker inside the fuel filler door that list the correct tire pressure. The fuel door sticker list 33 front, 29 rear as normal tire pressure with 44 being the max for both.

 

[SSBGLA45]

For a US spec 2015 GLA45 with 19" summer performance tires (NON run flats), the sticker on the side of the fuel door notes tire pressures (depending on number of people and amount of baggage on board) from (front-rear) 35lbs/32lbs to 36lbs/36lbs. The is no max inflation noted. On the tires themselves (19" Continental ContiSport) there is a max pressure noted of 51 lbs which would be for tire mounting purposes.

 

[WhiteRabbit]

Do NOT use the tire pressure numbers listed on the door jam.
Those numbers are the maximum tire pressures.
Only use the tire pressure numbers listed on the fuel filler flap.

For my USA 2016 GLA 250 4Matic, they are Front 33 PSI, Rear 29 PSI for normal loads.

 

[Enklein]

First what tires and size is on your GLA? Do you have run flats or performance tires? Is it a US spec GLA and the reason I ask is there are many variants of the GLA depending on the country of delivery. With that said I have not heard of any spec for 44 lbs and the norm is 36 lbs (understand the manufacture has to balance ride comfort-performance (as in handling)-mpg performance-tire tread wear so the inflation specs reflect those parameters). Point being is that your tire pressures you noted are fine and do not 'damage' your tires. I do not run my tires at 35 psi but rather at 32 psi…I do not care about mpg performance/tread wear but do care about performance.

You should verify where you are seeing this "44 lbs" spec

Tire size 235 45 R19. I have the H rated run flats Continentals. US Spec.
The 44lbs spec is on the door jamb.

 

[Enklein]

As I recall, there is a sticker inside the fuel filler door that list the correct tire pressure. The fuel door sticker list 33 front, 29 rear as normal tire pressure with 44 being the max for both.

I actually saw that. Thanks! Will drop the pressure back to what it shows as normal load from the numbers inside the fuel filler door.

 

[Enklein]

Do NOT use the tire pressure numbers listed on the door jam.
Those numbers are the maximum tire pressures.
Only use the tire pressure numbers listed on the fuel filler flap.

For my USA 2016 GLA 250 4Matic, they are Front 33 PSI, Rear 29 PSI for normal loads.

Got it. Looks like 33/29 PSI are my golden numbers. Thanks!!

 

[Enklein]

Thanks everyone for your responses!!

 

[Kcgla]

Do NOT use the tire pressure numbers listed on the door jam.
Those numbers are the maximum tire pressures.
Only use the tire pressure numbers listed on the fuel filler flap.

For my USA 2016 GLA 250 4Matic, they are Front 33 PSI, Rear 29 PSI for normal loads.

Got it. Looks like 33/29 PSI are my golden numbers. Thanks!!

Funny but I've noticed a consistent variation on fuel consumption with 32 vs 36 psi with the latter being better (i.e., about 3 miles per gallon more). And after a few months I decided to run all four with 36 psi

 

[2015GLA250]

38/34 seems to work for me. 18" run flat tires.

 

[Tim]

Tire Pressure dash notification

I have 19 inch run flat Goodyears that came on the car from the factory. I have about 40,000 miles now. At my recent oil change I elected not to rotate them at the dealer. Since I will be purchasing new tires after the heat of summer is over and before snow fly's. On my way home from the oil change I had to drive on some un-even asphalt overlay for about 20 miles. One wheel 2-3 inches higher than the other. My tire pressure notification came on. I don't remember the exact numbers. But it was in the 35 psi to 36 psi range for all of them. Today I was trying to even them out which I had to do once before. It seems really hard to get the exact amount in each tire. Is there a trick?

Door decal: 44psi max front and back, 33 front 29 back
Gas door: 44 psi
Tire: 51 max. PSI

I filled them all up to 45PSI. I will probably loose all of my fillings on the commute home.

 

[Boxster986S]

Are you trying to make the pressures even using a tire pressure gauge or by looking at the dash readout?


I've had better success using a tire pressure gauge at the valve stem. I don't know what the update rate is on the dash readout. I doubt that it is showing real time data. It more likely has an averaging algorithm in the software that controls the display. Otherwise you would see the tire pressure numbers constantly changing by +/-1 which gets annoying.


Remember that what the tire pressure system is looking for is a deviation from the defined set point. You can reset that value following the instructions in your manual.

 

[gbarringer]

Just took delivery of a GLA 250 front wheel drive. The door jam has 44, the gas lid as 33 and 29 and 44 has max. Owners manual says 44 for max load and up to max speed. I have 19 inch all weather Conti's ProContact GX SSR run flats, 235x45x19

 

[gbarringer]

OP question about warranty problems in the future. Yes there could be if the tire shows bad wear due to wrong pressure. Tire over inflated will wear in the center tread while under inflated will wear out on the shoulders. If you try to get replacement on warranty and either wore out in one area and good in another area than they can reject based on tire wore out. Wear on correct inflated tire and wheels with correct alignment will wear even across the tread. You should check tires after some thousands of mile for even wear and adjust pressure using the above for center or shoulder wear or have a wheel alignment if wear is just on one shoulder or you see feathering and not wear even.

 

[GLA415]

I read the fuel door on my 2016 GLA45, and based on how many people and how much load I carry on average, I decided to run all four at 36psi. It's been a tad more comfortable compared to what it was leaving the dealership (all four at 41psi?!), but still makes for a pretty hard and bumpy ride. Would lowering the pressure more make a difference in comfort?

 

[Kcgla]

That's the pressure that I'm using and it's quite alright. Also I have found that I'm getting a pretty decent overall fuel consumption at a moderately high tire pressure.