MPG dropped by 2 after new tires?

[Volvoholic]

Hahaha! If I were getting that kind of mileage out of mine I wouldn't complain. I get as low as 13.5 city sometimes...it pains me. That's mostly short distance, heavy traffic driving and people in LA + rush hour =

[passleft]

Ouch, 13.5??? that's scarey. but I bet you have better weather and get to use your sunroof more than I do.

[Volvoholic]

Yea, I'm 14-16 city 90% of the time. It's harsh. I probably do, basically any day it isn't raining...which is everyday in LA lol

[Astro14]

My wife gets about 21 (calculated using the trip computer) in mixed city/highway - she's a good driver, not a leadfoot, not a slowpoke...and pretty consistent...it only gets about 23 on the highway on longer trips, but I reckon that's due to the mechanical drag of all those driveshafts turning...

[Skater]

I've had to do quite a few repairs to my XV70 over the past 2 months. Everything was status quo until I replaced the Dunlop Signature Sports tires (OEM size) with Nokian WRG2s 235. I have been pushing the car a little more than usual (translation - spirited driving) but not to the extent that I expected to see my MPG drop from 23.x to 21.3.

I realized this the other night when adjusting the display after the service needed message came out. Is this possibly just a miscalculation or did the MPG really drop with the larger tires?

If no one else has seen this type of a drop with large tires any suggestions on what I could check that could be causing this?

Here's the list of what I've done since Dec:

-Fuel Pump
-Lower Control Arms
-Rear brake pads
-Nokian WRG2 235/60/16

Your new tires are 2.5% larger in circumference, so the mileage your odometer reads is 2.5% shorter than the actual distance travelled. That accounts for some of the perceived mileage drop.

[BiasedWaffles]

How in the world do you guys get "25-100" mpg? I filled my tank, set the trip odometer, and got 300 miles on a full tank. about 18 MPG, and that was 25 percent in town, 75 percent on highway

[Volvoholic]

How in the world do you guys get "25-100" mpg? I filled my tank, set the trip odometer, and got 300 miles on a full tank. about 18 MPG, and that was 25 percent in town, 75 percent on highway

25-100? I get 99.99 on a downhill if I coast lol if you look at my posts, I get anywhere from 13-16 city and I've gotten as high as 32.5 on the highway. Usually it's 20-26. 20@80mph, higher the slower I got obviously.

[BiasedWaffles]

25-100? I get 99.99 on a downhill if I coast lol if you look at my posts, I get anywhere from 13-16 city and I've gotten as high as 32.5 on the highway. Usually it's 20-26. 20@80mph, higher the slower I got obviously.

I was just joking, its as if every auto forum I visit people exagerate and say, "yeah, my Western Star truck gets 70 MPG when Im doing a cart wheel and driving with my elbow"

[passleft]

Your new tires are 2.5% larger in circumference, so the mileage your odometer reads is 2.5% shorter than the actual distance travelled. That accounts for some of the perceived mileage drop.

Actually the difference in these tires versus stock is about .3% difference... not enough to even mention.

http://www.discounttire.com/dtcs/infoTireMath.dos

And I've done the math after a few fill-ups and it's about a 2 MPG drop...

[Skater]

Actually the difference in these tires versus stock is about .3% difference... not enough to even mention.

http://www.discounttire.com/dtcs/infoTireMath.dos

And I've done the math after a few fill-ups and it's about a 2 MPG drop...

Assuming your stock tire was 205/65/16, and you replaced with a 235/60/16, the difference in circumference is +2.5% according to a different tire size calculator. I plugged in these numbers into the link you provided, and see there is a 0.3 inch in sidewall height, but it does show a 1.91 difference in circumference, which is +2.3% difference. I don't know where you got 0.3%?