What tire pressure do you normally use on your GLE450e
Fuel cap says Front: 35 /38 (normal /max load)
rear: 35/50 (normal/max load)
I would like to get some suggestions.

 

My 2024 GLE 450e gas cap says 35/35 front/rear and 38/50 full load. I run my tires at 36/36

 

My G550's fuel flap sticker includes stick figures indicating 3 people / 3 bags (normal) and 5 people / 5 bags (max load). If you plan to haul max passengers and cargo (and maybe a trailer) a long distance, increase your rear tire pressure. Otherwise, the lower value +/- 2 psi will do. If you plan to run on the low side of normal, you might need to reset your TPMS so you don't get low pressure warnings.

 

We run 36F 36R and have 10k on car (mostly highway). I’m guessing tread wear is already passed the half way point especially on the rear. May change to a higher pressure on the rears. Im guessing we will only get 18k miles on the first set of tires. Dealer saying the 450e’s are chewing threw tires.

 

The 450e weighs additional 700 lb over the 450. It's going to wear out tires faster.
In fact another push back against EVs is the amount of tire wear and particulate pollution (<PM2.5), and also the increased need for petroleum products because of that.
(Ironic, huh?)

 

The door lable says the rear tires are to be at 50 psi...does not state load?





 

With Mercedes, the door post label only states maximum pressures for the installed tires.
The gas flap is the recommended pressures under various loads and speeds, specifically for your car.

 

Thanks for the info. Decided 35 psi front and 38 psi for rear and see how it drives. Road trip from Vancouver to San Diego in June.

 

An unrelated FYI, parts of the road in Big Sur are still closed
https://www.bigsurcalifornia.org/hig...onditions.html

Enjoy the scenic road trip.
​​​​​​

 

Back on topic:

On Monday March 17 I drove from Long Island to Vermont. When I filled up in Springfield, Mass, I hit for me a new record an range: over 700 miles! that is about 35 mpg:

Temperature 47 degrees
Average speed 65 mph. This included local traffic plus driving on I -95 at about 70/75 mph
Tire pressure: 35 psi when cold
Tires: Pirelli Centurato P7 run flats
Gas: Costco regular
Weight: driver plus about 100 lbs of ski equipment
conditions: dry

 

I personally do 40/45 front/rear in my GLE450 (21" wheels, 275mm front/ 315mm rear tires). To me, that's a good enough compromise between ride comfort and ride firmness. Tire wear thus far (6000+ miles), seem to be very uniform, front/rear (staggered and hence non-rotatable).

I dearly wish Michelin came out with the same size tires in their Michelin Pilot Sport A/S 4 format, but unfortunately, the only tires that Michelin puts out in that size, which is also an All-season/all-weather tire, is their Primacy tires, which are a wet noodle at best, in comparison to the Pilot Sports.

The Pilot Sport A/S has fantastic grip in dry conditions, and unreal grip in wet conditions, in addition to being serviceable in light snow. Unfortunately, they just don't come in the 21" tire sizes that MB has put on the GLE. I got Yokohama Geolandar X-CV tires, but they don't hold a candle to the capability of the Michelin Pilot Sport A/Ss.

 

@Roweraay Wow that's a lot of pressure. I'd expect traction, even on dry roads, to suffer - never mind the harsh ride.
Have you tried the gas flap pressures?

To everybody else, just a reminder that the door post stickers are Fed required stickers, related to max pressure for that tire, not pressures recommended for the actual car.

 

Mercedes engineers spend a lot of time testing cars to determine everything from the optimal tire pressure to the minimum octane for the fuel. I go with what they recommend. Seems to work just fine.

 

The recommended tire pressures on my front door post is 38/45 front/rear. That is of course for the standard 20s.

I replaced the 20s with 21s (not sure what the number is for the 21s), but either way, I don't think it should be too far off either.

Please note that the Max cold Pressure for the tires are 50psi. Both on the OEM 20s, and also in my replacement Yokohamas. And also in the aforementioned Michelin Pilot Sport A/S 4s. So the door numbers have nothing to do with the Max tire pressures......those are the MB recommended front/rear tire pressures, and my front tires have an additional 2 PSI over their number.

 

Worth mentioning, pointing out heavy model and expensive - yet OEM there is no front Camber or Caster and no rear Camber to adjust tire contact angles, spread load more evenly to counter excess edge tire wear. Also tires are “non rotatable”.

It is all to do with cost savings and ever increasing speed of new car assembly lines. Stopping to adjust / set Camber and Caster is no longer an option.

Now instead one only setting - at showroom height. No ongoing adjustment for high cambered roads with excess passenger side edge wear or inner wear both sides through altered height / load carrying. Excess outer edge wear through spirited driving. Or adjustment for curb knock damage !

The often quoted reassuring “Full Front & Rear ‘4’ wheel alignment” is in fact now only basic TOE “directional” adjustment. It is new car industry’s best kept secret.

We saw the need therefore and manufacture Front Camber and Caster Bolt-On kits and also Rear Camber (and extra Toe) adjuster kits.

No special tools required to install and no need for control arm removal.

SEE SPOILER






AUDI to VOLVO - Experience Resolving OEM Suspension Shortcomings (and costs) Since 1964 !

 

Ignore the door post pressures because that's a federally required sticker specific to the tires the tires, not the car.

Gas flap pressures are specific to the car.
Since you've changed from 20s to 21s, neither sticker applies.

Maybe someone with a 450, steel springs (I think that's what you have) can post what their gas flap pressures are.

But gosh, that's a lot of pressure that you're using. It'll compromise the impact resistance of the tires, tread life, traction, and also encourage squeaks and rattles.

The max cold pressure is also posted on the tire, but its primary intent is to restrict that pressure while installing the tire and setting the bead.

 

I guess this is why I hesitate to buy a used car that requires 91 octane. People putting regular in a car that requires premium. Unless of course the 19 didn’t require premium.

 

The 2019 E450 was a Bi-Turbo V6. I would be shocked if the manufacturer recommended anything other than premium.

I personally put premium (mostly from Shell) even in my 2019 Honda Fit with a Naturally aspirated 1.5L 4-cylinder engine with a stick-shift, since the compression ratio of the engine is 11.5:1, and it can absolutely use every bit of the higher octane fed to it.

And the only reason why the manufacturer allows regular fuel in the Honda Fit with its high-strung Honda engine, is for marketing purposes, and to pull it off, they probably have an array of knock-sensors that severely retard engine timing, when knock/damage happens with less-than-optimal fuel. Not good for the engine, and not good for mileage either. I personally get between 38-42mpg in the Fit, while the EPA mileage for the Honda Fit with the Stickshift, is 29/36 and 31 combined.

 

From the manual, premium is recommended not required. I have used premium and the mpg was the same and I did not notice any difference in performance. I do not drive aggressively.

I realize that there is a loss of 5% to 7% going from premium to regular: that means there is a horsepower drop from 365 to 340. Unless I am racing, flooring the car from a stop light or driving above 120 mph I will never miss or use that extra 25 hp.

As to the Honda: do not know what is recommended. If regular is recommended, then putting in premium is a complete waste of money. I also have a Ford Edge Sport, (now called the ST) with the 2.7 liter eco boost engine. The engine puts our 335 hp. Ford recommends regular. Putting in premium, where the engine is designed to run on regular, will not change the performance of the engine.

see: https://www.google.com/search?q=usin...hrome&ie=UTF-8

 

“Recommending” regular in a 11.5:1 compression engine, is really meant for the lowest-common-denominator of the population. It is a marketing exercise, since if they recommend what the engine truly needs, the car will not sell. Specifically in the market segment that a car like the Honda Fit competes in.

So Honda, as with all such manufacturers, will put in hyper-aggressive knock sensors that will aggressively retard the engine timing, just so that the car can match upto what the marketing literature necessitated Honda to “recommend”. Yes, the power will get drastically curtailed by the engine management system, once knock is experienced and the knock-sensors get triggered, and the engine timing gets retarded…..do that regularly, and the engine will always be driving with the equivalent of “one hand tied behind its back”, to prevent recurring damage to the engine.

Once you move beyond the “lowest common denominator” of the population, and you start looking at the engine specification, and understand what a 11.5:1 compression ratio in a Normally Aspirated engine is, you will realize that putting regular fuel into such an engine, is hog-tying its true capabilities. Just so that the marketing folks can feel happy that they were able to get away with “recommending” regular. And the engineering folks behind the scenes, can feel relieved that they were able to put in hyper-aggressive knock sensors to salvage the engine from incurring recurring damage, just so that the idiots in marketing could get away with “recommending” regular……under the understanding that the engine will never operate to its design potential, due to the timing retardation triggered by the knock sensors, especially when the lowest-common-denominator follows the manufacturer’s “recommendation” and put in lower grade fuel.

Au Contraire, I agree that in a normally aspirated engine with a 9.5:1 compression ratio, where the manufacturer recommends regular, they are absolutely spot on. Putting premium in such a vehicle, would not add any value.

 

In theory I agree with you: an 11.5 to compression engine running on regular will require significant spark retardation to avoid pre-detonation. But engines even with an 11.5 to 1 compression ratio can be designed to run on regular.

Having said that, have you run a controlled test of the difference between regular and premium in your car? Not "seat of the pants" but a controlled test as to mpg and acceleration?

My Edge Sport, 2.7 Eco Boost Twin Turbo engine, has a compression ratio of 10 to 1: regular fuel is recommended. As you correctly point out, putting in premium would be a waste of money.

 

I don't understand why people buy an $85,000 car and then go cheap on things like gasoline. This warning is from my 2024 GLE owners manual.

 

Same thing is in my manual.

I never go over 2500 RPM and never drive my car hard. In fact my individual settings are: steering sport; ride comfort: engine economy

The reason why I own a $75K car and put regular gasoline in is quite simple: My parents were of the depression era. I heard how hard it was, how rich and poor lost everything. It was drilled into me to have no debt and wherever possible save money. I still wash my own car rather than pay $30 to the car wash, change my own oil for $60 rather than pay $225 to the dealer: This is way I am built.

Just my $.02

 

The additive package in premium fuels is superior - that alone leads me toward the extra expense, since I expect to keep the car for 90k miles at least.

I also go out of my way for Shell, because I get better MPG (+2 is normal) and seat of the pants performance. (Shell is getting out of the gas station business, according to a retired Shell engineer I know - drat.)

If I have a loaner car that I have long enough to run through a full tank there is a MORE THAN SIGNIFICANT difference when I fill its tank with Premium. It's like a different car altogether.

It does net out to about $60/1000 miles increased cost, but I've made a big investment in the car and I want to take care of it. (At current prices.)

I also came from Depression Era parents, but I save my money by paying saving up to make a cash purchase, and giving my steed the best care possible. My Depression Dad adopted my practice when he saw how long my cars last. My best - 700,000 miles - an FJ45 Land Cruiser pickup, 1 of less than 500 solid new in the US.

I also buy the best paint for my house and skip the builder-grade flooring, but that's just me.

 

I came from depression era parents also. My dad didn't have electricity in his house until 3rd grade. He taught me that proper maintenance of equipment was the best way to save money on equipment. One of his favorite sayings was that "some people would step over a dollar to pick up a dime."