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New tire equal 30% drop in milage

I recently purchased new tires for my 2013 Corolla. I was getting up to 600 KM per tank now I’m lucky to get 450KM per tank I went from 6.3l/km to 8.4l/km. I have changed nothing else. I have 65000km on the car and feel like I should change the fuel filter but my would the milage drastically?

Are you able to tell us the make and model of the tires that came on the car, and the size including all the numbers and letters and load rating, and then the same information about the new tires?

Also it wouldn’t hurt to check the air pressures.

Am I to understand that every time you fill up the tank it holds exactly the same amount of fuel?

Assuming that the engine is not in need of maintenance or repairs–such as spark plug replacement or thermostat replacement–and assuming that the tire pressure is not a lot lower than it should be, I think the obvious conclusion to draw at this point is that the new tires have a much higher rolling resistance than the old tires did.

I am always amazed at how few people actually research the rolling resistance of tires before purchasing them.
Did you research that factor?

And, as was already stated, it would help if we knew the make and model of both the old tires and the new ones.

You would think that with the web search people would know how to actually determine their Miles per Gallon.

Can you also tell us where you call home?
The recent arctic weather has been KILLING my mileage!

yeah, I’ve seen drops from 32 MPG or so to 28 or less.

The old tires were Firestone and the new ones are Michelin. The car tells me the milage I’m getting so it doesn’t matter how much fuel I add it will always tell me the mileage and how many km are remaining. The car gets regular service at the dealership and the tires are all 35psi

I live in Edmonton Alberta and I understand the cold makes a difference but this is ridiculous!

If you are not resetting your read out do so each fill up. Also keep it the old fashioned way to see just how accurate the readout is. Do this for at least four tanks. I feel you don’t really have as big a problem as you think.

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Thanks for the advice. I will check the old fashioned way but I have reset with each tank of fuel and it’s actually got worse each time since the new tires were installed less than 2 months ago

You keep talking about how far you drive. The KM per gallon is the important number.

Tire companies sell dozens of different models of tires, “Michelin” doesn’t indicate what type of tires you have.

Putting your mileage in familiar terms for myself you went from 37 MPG to 28 MPG, this cars fuel economy rating is 29 MPG combined city/highway.

If you are using winter tires in very cold weather your fuel economy seems better than expected.

That’s the number that worries me the most I’m using more fuel per km than ever

This is the worst milage I have got in the 3 years I have owned the car. When I purchased it I was told it would get 50mpg. I never got better than 37

Well if you believed that I have this bridge in Brooklyn I would like to sell.

The Government of Canada publishes fuel economy ratings for cars, you don’t have to rely on rumor;

I don’t believe that is impossible to get 50 MPG with that car but very unlikely for the typical driver.

Actually, in the US, fuel economy is measured in terms of miles per gallon

Elsewhere, it’s measured in liters/100km . . . in other words, how many liters of fuel are needed to drive 100km

When OP stated “went from 6.3l/km to 8.4l/km” I believe he meant the fuel economy went from 6.3 liters/100km to 8.4 liters/100km. That is indeed a significant reduction in fuel economy

First, everything else being equal, new tires do not give as good of fuel economy as worn out tires. That’s because a tire’s rolling resistance is greatly affected by its mass.

Second, I’ll bet you took off OE tires (the ones that came on the car new from the factory) and replaced them with tires that were rated for better wear. There is a technology triangle involving treadwear, traction, and rolling resistance. To get good results in one area means sacrifice in another area (or both areas!) The tires on new cars are spec’d by the vehicle manufacturer to give good fuel economy, but they don’t care about wear - while the tire manufacturer doesn’t care about fuel economy but needs to stay competitive in the wear category, so the tires they supply to tire dealers are quite different than the tires spec’d by the vehicle manufacturer. There is a huge disconnect between these 2 groups and it shows in the tires,

Third, this time of year can reek havoc on fuel economy - not only because the cold weather takes more energy to heat up the car, but the fuel is different - and worse for fuel economy. This would be a terrible time to try to draw conclusions on fuel economy.

And if you took off high grip tires and replaced them with good wearing tires, you’d be taking another hit in the fuel economy area.

So lots of reasons why you might be experiencing poor fuel economy.

He’s also talking about imperial gallons. A U.S. gallon is roughly 8/10ths of an imperial gallon. An imperial gallon goes about 1-1/4 times as far as a U.S. gallon. Mpg is correspondingly higher.