Tire pressure
 

Good day all. I have a 2017 E300 which has been problem free for me since purchase in June 2017. However, recently there seems to be a slow and gradual loss of tire pressure in all 4 wheel.I first noticed it (albeit only in 2 tires) about 4 months ago, I leveled off the air pressure in all 4 tires to 32 psi. Now I'm showing 26 lbs psi in all 4 tires and once again will fill them all to the same pressure. Has anyone else experienced this problem. Any input would be appreciated before I take the car to the dealer. Thanks

Over what period of time are you seeing the loss of air? Also as it's getting cooler, are you seeing this now that's it's cooler weather?

As a general rule for every 10 degree drop in temperature there is a drop of 1 lb/psi.

However my experience with low profile tires (I have Boxster) is that the loss of pressure is greater then 1 lb/psi per 10 degrees: I assume that is because of the lower volume of air in the low profile tires.

On my E350 for every 10 degrees I lose a minimum of 2 psi: the Boxster 3 psi and the Ford Edge Sport between 1 and 2 lbs.

Several years ago when we experienced a drop of 25 degrees overnight the warning light came on advising me of low pressure in all four tires.

I have an air compressor and at this time of year I add air to my tires on a regular basis.

Just my $.02:

I keep my tires 10% higher than the suggested pressure: I find little to no difference in the ride quality. On the other hand, gas mileage goes up 1 to 2 mpg. Old trick I learned many years ago driving trucks!

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

Your experience mirrors mine. This is why I asked the OP if the weather has cooled where they are? I also inflate a tad higher.

Thanks all for your input. Strange thing is that I had no issues throughout my first year. I think I'm just going to but an air compressor to inflate tires at home instead of running to the gas station. Any recommendations? I see a number of them on Amazon although I also see on one of their top choices some have had issues with the 12V plug in charger. Thanks again for replies. BTW, I had a worse problem with my prior BMW including many false alerts.

Mine is real compressor (expansion tank) that runs on 120 volts Bought it several years ago at Sears. I think it was about $99 on sale. I have three cars and do not have the time to go to a gas station. Luxury yes - but worth every penny!

I use an old (circa 1955) paint sprayer to keep my tires at the proper pressure. It also inflates pool toys, etc. It is very quiet. That's something I can't say about current compressors.

I have noticed the TPM is sensitive in these E's, so I just ordered one of these on Amazon:

I have something similar to that and it works well. Noisy little thing but it works.

I recently purchased this portable air compressor from Amazon - works great.

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My Porsche came with one of those small compressors. They were OK for an emergency, but took forever to raise a tire pressure by 5 psi.

Mine only takes about two or three minutes to raise the pressure 10 psi.

My paint sprayer setup takes about a minute to put 5 psi into 245/45x18 tires.

That's nice, but I don't think this is a competition about who can add air to their tire faster.

I was simply commenting on how long those 12v dc compressors take to fill a tire. 3 minutes is a long time to add 10 psi to a tire. BTDT

The thing won't break and I can plug it into the 110v outlet in the E300.

I just ordered the same one. Since I anticipate more problems in the cold weather, I wanted to inflate the in the garage. Since the 12 v require the car to be running, I wanted a 120v so I could stay in the garage, and this unit seems to fit the build.

I actually bought one of these and find it works well for topping off everything from barn carts and pool toys to the horse trailer and everything in between. Easy to use. The hose treads on to the tire valve stem so you can set it and forget it. It's noisy, but for the price, I'll put up with it. For big task I have a compressor.

I check tire pressures almost daily using the Service menu tires selection.

You have to love Amazon Prime. I ordered this yesterday and it was just delivered. While I haven't tried to add air to a tire, I must say it's much quieter than I expected it to be. This one seemed to have the most reviews and they were very positive. I like that it's 12v or 120v operated.
https://cimg4.ibsrv.net/gimg/www.mbw...462c88cdf5.jpg
https://cimg3.ibsrv.net/gimg/www.mbw...dad167fb28.jpg

Same here. Ordered mine yesterday on Amazon Prime and it's being delivered today! I also ordered a digital tire gauge since I'm having trouble reading the old fashion pop up one. Whatever happened to the days when you filled your tires once "in a blue moon". Maybe it was out of ignorance because cars weren't equipped with TPM but we never seemed o have a problem. Then again, we all used to take a drink from the garden hose on a hot summer day and amazingly survived that which we're told today will kill us. Oh well

Low profile tires.

On my Ford Edge, only have to fill the tires once. On the MB, once every month.