Sub2007 standard engine. What could possibly cause sudden change in MPG ? I have done some mechanical work but most of it was unrelated except break pads. Replace them at the shop , just front. Since then the disks become very hot. When driving in town for 1hr they are hot to burn a finger when touched.

I just have this car for 2months and it seems that MPG was around 28-30. Recently it dropped  to 21-24. Is it possible that hot breaks could cause that ? I bought the best after market available. I'm thinking about putting the old ones back, they were not to bad yet.

If brakes are getting hot sounds like brakes are dragging  did the shop take out and clean /  lubricate  the  sliding pins that the 2 caliper bolts screw into?

I think vI should never see this shop again. They did not lubricate anything. When I stopped there they checked calipers and sais they are bad. Since I was watching what the mechanic is doing I kinda believe this was the case, but it is hard for me to understand that the breaks were working fine until the moment I decided to replace the pads. How is this possible that both sides went bad just by replacing pads ?

I ended up replacing both calipers. After it was done but the wheels were still off I tried to move the drums and it was kinda hard to move them. Before the replacement after I pressed the break the drums were getting completel locked so it was not even possible to move them.

I do not have experience witht this car so not sire how easy the should turn.

The bottmo line however is that replacing calipers did not really changed MPG much. It went up from 21 to 23.

I don't know whar else might causing it. When I bought this car  2 months ago I was quite happy about gas with MPG around 30. Now it is a disaster.

Wonder if I go to the friend and he connects computer if it will show anything.

Edited October 4, 20169 yr by sadarahu

I tried to put the car on N gear and it seems to roll smoothly but not sure how light the wheels should move. aslo - is it normal for the rear wheels to get warm. The drums do not get very hot as the front but warm. I have no idea what else could cause such a drastic change in MPG

I also replaced drive shaft but it is hard to believe this could be the cause

The wheels should spin freely. The added friction of the brakes dragging is why your mileage has gone down. They maybe did not properly adjust the calipers to accommodate new thick pads. I think that the Subaru calipers get turned with a tool to adjust them. Maybe the mechanic hadn't done many Subaru brakes and just forced them on.  How many miles have you put on since? Either go to a Subaru specific shop and tell them the story suggesting they check the caliper adjustment since they are dragging, or wait until the new pads wear down enough.

They probably swapped to the winter blends of gas in Chicago.

Sub2007 standard engine. What could possibly cause sudden change in MPG ? I have done some mechanical work but most of it was unrelated except break pads. Replace them at the shop , just front. Since then the disks become very hot. When driving in town for 1hr they are hot to burn a finger when touched.

I just have this car for 2months and it seems that MPG was around 28-30. Recently it dropped  to 21-24. Is it possible that hot breaks could cause that ? I bought the best after market available. I'm thinking about putting the old ones back, they were not to bad yet.

 

It sounds as if the garage guys just jammed them ( the new pads) in without doing any of this.

 

The brake caliper pistons need to be compressed back into the caliper in with a G clamp using an old worn pad in order to get the new pads to fit in to the caliper and  around disc. 

 

Fluid will also need to be removed ( with old syringe) from main brake fluid reservoir  while compressing caliper pistons otherwise reservoir will overflow.

The  2 caliper pins that the caliper bolts thread into need to be removed - cleaned and regreased as well  ( small rubber bellow seal protecting the pin insides)  otherwise uneven braking  by pads / uneven wear of pads .

 

This is how my 01 2.5  Outback was so imagine  07 would be similar.