New Tires = Lower MPG???? Help!!

s.e.tx_parrothead · 06-10-2007, 12:51 AM

Got new tires on Maggie about 3 weeks ago. On the way to the dealership was getting 51 mpg and after getting Maggie's "New Shoes" the MPG started going down hill. On the way home, was struggling to get 45-46mpg. Don't know if this is normal or not, but after 3 tanks of gas, I am still averaging about 45-46. With the old tires, I was averaging around 49-50. I live about an hour north of Houston and I have had to run the A/C due to the high humidity but I run it just enough to cool down the cabin and then I turn it on to a lower fan speed. I have the temp set to about 77 degrees which is comfortable for me (little warm for the hubby).

I put the same ole Goodyears back on the car since I have the Extra Mile pkg. I am not sure if they did an alignment or not but I did check the air pressure about a week after the install and three tires were at 33 and one was at 30. I bumped the front two to 39 psi and the back two to 37 psi. If I fill up the car on the way home and check the mpg when I pull in the drive way, it is back up to the high 40s but as the week/tank wears on it drops. I drive the speed limit or a mile or two over (do use the cruise) and the commute is rather hilly.

I am at wits end wondering if just the A/C running a bit more caused the drop or what happened. Any suggestions????? Oh, have just under 32,000 miles on the car. Got the oil changed about 3 days prior to getting the new tires. Haven't done the officially sanctioned Toyota 30, 000 mile service at this time.

Thanks-
Kris

**TonyPSchaefer** · 06-10-2007, 11:45 AM

There have been reports of new tires lowering mileage. Since I haven't changed tires, I don't know directly.

About the tank/week wearing on and the mileage dropping, as goofy as it sounds I truly believe that when I'm super-sensitive about mileage I actually hinder my own mileage by worrying more about it and working too hard at it. Sounds silly, I know.

About the A/C, because it is not hooked mechanically to the engine, it doesn't draw directly from it. However, running the A/C does draw from the battery which will reduce the State of Charge and may cause the engine to run more to recharge it and limit your stealthing distance.

Rangerdavid · 06-10-2007, 12:14 PM

Hi Kris:

I remember reading several posts on here in the last year about new tires, and the reduced mileage until the "new" wears off the tires and they are broken in a bit. I'll look and see if I can add a link to one of the posts for you, but all else being equal, sounds like its just new tires and that should change after you get 2500 - 5000 miles on the new tires.

Good luck, and I like your avitar, Buffett rules !!

jamesl · 06-11-2007, 11:17 PM

Kris you didn't say what was the brand and type of tire you put on that is getting the lower mpg....

s.e.tx_parrothead · 06-12-2007, 12:13 AM

I guess I just need to be patient...Not real good at that

I will forget about it and see what happens after the 35000 mile oil change. I know that as soon as the Extra Mile pkg is up, I am probably going with something other than the OEM Goodyears.

RangerDavid, glad you liked the avitar. It is off a Caribbean Soul T-Shirt. We were lucky that JB made it to Houston for the Bama Breeze tour. He opened the tour there at Minute Maid. It was good, but I miss the smaller venues...The acoustics are better. But oh well it is JB!!!!!

Thanks again!
Kris

06-10-2007, 12:51 AM	#1
s.e.tx_parrothead Senior Member Join Date: Mar 2006 Location: Huntsville, TX Posts: 130 My Car: 2006 Prius Model: Package: #7 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Got new tires on Maggie about 3 weeks ago. On the way to the dealership was getting 51 mpg and after getting Maggie's "New Shoes" the MPG started going down hill. On the way home, was struggling to get 45-46mpg. Don't know if this is normal or not, but after 3 tanks of gas, I am still averaging about 45-46. With the old tires, I was averaging around 49-50. I live about an hour north of Houston and I have had to run the A/C due to the high humidity but I run it just enough to cool down the cabin and then I turn it on to a lower fan speed. I have the temp set to about 77 degrees which is comfortable for me (little warm for the hubby). I put the same ole Goodyears back on the car since I have the Extra Mile pkg. I am not sure if they did an alignment or not but I did check the air pressure about a week after the install and three tires were at 33 and one was at 30. I bumped the front two to 39 psi and the back two to 37 psi. If I fill up the car on the way home and check the mpg when I pull in the drive way, it is back up to the high 40s but as the week/tank wears on it drops. I drive the speed limit or a mile or two over (do use the cruise) and the commute is rather hilly. I am at wits end wondering if just the A/C running a bit more caused the drop or what happened. Any suggestions????? Oh, have just under 32,000 miles on the car. Got the oil changed about 3 days prior to getting the new tires. Haven't done the officially sanctioned Toyota 30, 000 mile service at this time. Thanks- Kris __________________ "It's the sound of the low tide, the smell of the rain, Travelin' alone on my boat and my plane. Take it all in, it's as big as it seems. Count all your blessings, Remember your dreams." -- Jimmy Dreams "Maggie" Magnetic Gray pkg#7 w/leather upgrade, XM radio, MFD sunhood Hubby -- 1989 Toyota pickup 1999 Jeep Wrangler 2005 Toyota Tundra We share custody of the 05 Tundra and Maggie. I am no longer doing a long commute, the hubby is.

06-10-2007, 11:45 AM	#2
TonyPSchaefer Your Friendly Moderator Join Date: May 2004 Location: Far-North Chicagoland Posts: 10,497 My Car: 2004 Prius Model: Package: #9 Thanks: 39 Thanked 164 Times in 105 Posts Friends: 23	There have been reports of new tires lowering mileage. Since I haven't changed tires, I don't know directly. About the tank/week wearing on and the mileage dropping, as goofy as it sounds I truly believe that when I'm super-sensitive about mileage I actually hinder my own mileage by worrying more about it and working too hard at it. Sounds silly, I know. About the A/C, because it is not hooked mechanically to the engine, it doesn't draw directly from it. However, running the A/C does draw from the battery which will reduce the State of Charge and may cause the engine to run more to recharge it and limit your stealthing distance. __________________ Proud father of Priapus: the '04 Tideland BC9 with an OEM EV button and sense of self-righteousness Current Mileage Chicago Prius Group Website Chicago Hybrid Group on FaceBook Find me on faceBook

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06-10-2007, 12:14 PM	#3
Rangerdavid Senior Member Join Date: Jun 2006 Location: Boone, North Carolina Posts: 1,264 My Car: 2006 Prius Model: Package: #5 Thanks: 1 Thanked 9 Times in 6 Posts Friends: 25	Hi Kris: I remember reading several posts on here in the last year about new tires, and the reduced mileage until the "new" wears off the tires and they are broken in a bit. I'll look and see if I can add a link to one of the posts for you, but all else being equal, sounds like its just new tires and that should change after you get 2500 - 5000 miles on the new tires. Good luck, and I like your avitar, Buffett rules !!

06-11-2007, 11:17 PM	#4
jamesl Junior Member Join Date: Jun 2007 Posts: 14 My Car: Model: Package: Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	Kris you didn't say what was the brand and type of tire you put on that is getting the lower mpg....

06-12-2007, 12:13 AM	#5
s.e.tx_parrothead Senior Member Join Date: Mar 2006 Location: Huntsville, TX Posts: 130 My Car: 2006 Prius Model: Package: #7 Thanks: 0 Thanked 0 Times in 0 Posts Friends: 0	I guess I just need to be patient...Not real good at that I will forget about it and see what happens after the 35000 mile oil change. I know that as soon as the Extra Mile pkg is up, I am probably going with something other than the OEM Goodyears. RangerDavid, glad you liked the avitar. It is off a Caribbean Soul T-Shirt. We were lucky that JB made it to Houston for the Bama Breeze tour. He opened the tour there at Minute Maid. It was good, but I miss the smaller venues...The acoustics are better. But oh well it is JB!!!!! Thanks again! Kris