08Legacy-GT Posted November 20, 2014 Author Share Posted November 20, 2014 After an oil change from random what I bought with the car to RP high milage.. I'm showing like 2mpg better now! Interesting 2017 Subaru STI 2008 Subaru Legacy 2.5i limited Link to comment Share on other sites More sharing options...
BoozeRS05 Posted November 20, 2014 Share Posted November 20, 2014 So I did a 350 mile round trip from PA to MD last weekend. -Cobb stg2 -93oct -fresh 5w40 oil change -speed btw 75-80mph -obviously highway, but tons of elevation and speed changes, long rolling corners. -dragging rear caliper and bad rear wheel bearing -nearly spent winter tires on 17lb BBS wheels -roof rack with fairing ~23-24mpg Should have removed the roof rack. EB's Subaru journal - 2005 LegacyGT Wagon & 2014 Forester FB25 (2008 specB - RIP) IG@legacygtliving Link to comment Share on other sites More sharing options...
covertrussian Posted November 20, 2014 Share Posted November 20, 2014 Noticed my MPG on the dash is a bit lower lately, today it's reading 23.4 Filled it tuesday night at my normal station by the house, $3.44 for 93. Been doing my highway drive to/from work, did go to home depot yesterday. It has been much colder the past week too. That and the new much larger radiator, car warms up a little slower. Even last thrusday, I filled the tank drove to VT on saturday, still only got upper 24's on the dash. Filled it on Sunday about 23 miles from the house in MA, $3.13 for 93 octane. Damn cold weather and winter fuel. But the turbo likes the cold air... $3.44 per gallon? Man I do love my $2.95 here in VA (not Metro area). Check your tire pressures with the colder weather, they tend to go down around 1psi every 10*F. I used to blame winter gas, but I'm holding that back right now. I got my best city gas mileage the other day, in the cold and with winter gas. All I had to do is reduce the amount of cold starts I did for that fillup . I do blame the cold weather, I definitely saw a drop off in gas mileage once it started going below 60*F. So I did a 350 mile round trip from PA to MD last weekend. -Cobb stg2 -93oct -fresh 5w40 oil change -speed btw 75-80mph -obviously highway, but tons of elevation and speed changes, long rolling corners. -dragging rear caliper and bad rear wheel bearing -nearly spent winter tires on 17lb BBS wheels -roof rack with fairing ~23-24mpg Should have removed the roof rack. I would say that's actually very good mileage for those conditions. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
Max Capacity Posted November 20, 2014 Share Posted November 20, 2014 Oh Yea, I do have the 18" Spec B wheels and snowtires on now too. 60F you make me laugh...we haven't seen over mid 40's in over a week. Yesterday it did get up to freezing. Over nights in the upper teens. At least we're not getting what Buffalo is... 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
tanner12 Posted February 15, 2015 Share Posted February 15, 2015 My front brakes were dragging, I rebuilt all 4 calipers, so we'll see now. My rear might still be dragging because my caliper guide pin bushings are still old ones that let air through. Still sadly my 04 Forester XT with 60k more miles, shorter gears, less aerodynamic, still gets better gas mileage then the Legacy. It gets 18+ usually with same kind of driving. Any difference after the brakes? I've recently noticed a 3 mpg drop and my front brakes are due, so hopefully that's the culprit. I also had the wheel bearings done and a new cv joint in the front left, but still the decreased mileage. Changed the spark plugs, air filter, injector cleaner also didn't help. Any other ideas or recommendations would be appreciated, as I'm tired of chasing the problem Thanks, Tanner Link to comment Share on other sites More sharing options...
Akasa Posted February 15, 2015 Share Posted February 15, 2015 Winter MPG in my 05 5mt wagon is about.... 21-23 mixed running 93. I generally get around 24-26 in the summer. Sucks coming from a car that was able to get 53mpg with some serious hypermiling, but whatever, the GT has more than twice the torque and horsepower, I can't complain. Link to comment Share on other sites More sharing options...
covertrussian Posted February 15, 2015 Share Posted February 15, 2015 How recently? Like 3 months ago or within the last month? If 3 months then cold weather is to blame, religiously check your tire pressures (these cars are very sensitive to tire pressures). I didn't really gain any MPG with brakes rebuilding on my Legacy, but I didn't drive for too long with them dragging. I did gain 1-2mpg on my FXT with slider pins sticking due to expanded rubber on them. I removed the rubber and regreased them and that seemed to help. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
tanner12 Posted February 15, 2015 Share Posted February 15, 2015 How recently? Like 3 months ago or within the last month? If 3 months then cold weather is to blame, religiously check your tire pressures (these cars are very sensitive to tire pressures). I didn't really gain any MPG with brakes rebuilding on my Legacy, but I didn't drive for too long with them dragging. I did gain 1-2mpg on my FXT with slider pins sticking due to expanded rubber on them. I removed the rubber and regreased them and that seemed to help. It's been maybe 2 months, however I live in Florida and didn't have the mpg drop last winter. Forgot to mention I also cleaned the throttle body and MAF sensor. Link to comment Share on other sites More sharing options...
covertrussian Posted February 15, 2015 Share Posted February 15, 2015 Cleaning the maf actually would have something to do with it. Cleaned maf = more air read = more fuel added = more power. If your driving like your used to (our feet do have muscle memory), then your still over gassing it like you would when your down on power. Another thing is resetting the ECU, it's a must when doing anything related to airflow or timing. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
tanner12 Posted February 15, 2015 Share Posted February 15, 2015 As I'm a total noob, can I reset the ECU on my own? Link to comment Share on other sites More sharing options...
covertrussian Posted February 15, 2015 Share Posted February 15, 2015 Yeah, easiest way is through an OBD2 device like Tactrix or Cobb. Next way is to clear codes with an OBD2 code reader, though without any codes nothing will happen. Last way is to unplug the negative terminal on the battery for couple minutes. Last way loses your mileage and radio presets though. Usually ECU will relearn over time, and I would think 2 months has been enough time already, but who knows... 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
tanner12 Posted February 15, 2015 Share Posted February 15, 2015 It's also a 5EAT and I changed the transmission fluid with a valvoline synthetic about 6 months ago and did front/rear diff with extra S. Typical mpg has been 24, now at 20-21. Link to comment Share on other sites More sharing options...
covertrussian Posted February 16, 2015 Share Posted February 16, 2015 How many miles on the car, when was the last time you changed the spark plugs (and which plugs did you change to)? Have you changed gas stations, or do you use the same one? Has your driving style changed; more cold starts then before, shorter trips? 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
HDTurbo Posted February 16, 2015 Share Posted February 16, 2015 Colder temps make a difference. And make sure your ATF is full. Link to comment Share on other sites More sharing options...
tanner12 Posted February 16, 2015 Share Posted February 16, 2015 128,000. I did the spark plugs about 3 weeks ago to a Denso iridium plug, I can't remember specifically. Driving routes and gas stations haven't changed either. I've also used synthetic oil every 3000-3500 miles for the past 2 years. Bought the car at 90k. Link to comment Share on other sites More sharing options...
tanner12 Posted February 16, 2015 Share Posted February 16, 2015 Could an air intake leak be a culprit? I'm noticing a louder vacuum sound when accelerating. Link to comment Share on other sites More sharing options...
covertrussian Posted February 16, 2015 Share Posted February 16, 2015 Yup it definitely can be. Check your turbo inlet for rips. 05 LGT 16G 14psi 290whp/30mpg (SOLD) 12 OBP Stock 130whp/27mpg@87 Oct 00 G20t GT28r 10psi 250whp/36mpg 22 Ascent STOCK Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.