hello all...
i had my gd3 std tranny (canadian dx model) for 6 months now. Everything is great (or as expected) except for mpg (l/100kms)
no cels, no problems, no hiccups. engine seems in tiptop shape.
only thing it's at 8,2l/100km. if i go slow (-100km/h) i get better mpgs but when i cruise at 115/120km/h and do some city (rural roads) it stays at 8,5 +/- ,25. Power wise i knew what i was getting. I own a dc2 type-r and cars before were 99-00 si (sir in canada) and i had a sti swapped legacy wagon.

now dont get me wrong, i know the little engine does it's best to move the 2200# car, but i dont understand it need so much fuel doing so.

i logged some travel and my Long term fuel trim get as high as +9,2.(on long distance +50kms)
short term varies between +5 and +6.
car is stock except for ik22 plugs, valves were adjusted 4000 miles ago.

 

I just had a long highway trip 144 km one way and scored 38 mpg and I was going between speeds 100/120 km/hr all over the place.

Granted the 5spd the engine does spin a bit high at 100 km (3000 rpm) but take note when your engine speed is that high you don't need as much "throttle" to maintain speed. Usually feathering the pedal can maintain speed without hurting fuel economy so much.

I recommend a scangauge or some ODB II reader, you can get a lot more stats on how your engine is working such as engine load (which is usually 50% load on the highway in 5th gear, 80% when your going uphill or 30 MPG US when your drafting behind someone :P)

the fit is not the best areodynamic piece of work, but on the highway scoring less than 8L/100 km (30 mpg us) shoudn't be an issue.

 

well i'm feathering the pedal for sure (driving with the toes) load is it +/-60% at 110 km/h
all the mpg are calculated at the pump not by gauges.
i tried premium fuel (computers adds timing a little bit) but it does not rally helps (maybe -0,2 l/100) but it's not worth the extra price.
it's really the fuel trim that registers at +9 that worries me.
probably the winter gas and the 15'' winter tires does not help.

 

yea don't put 91 octane its a waste of money
you have a scangauge? sounds like just driving style needs some adjustment but winter tires can eat up mpg yes what's your tire pressure set at?

 

pressure is at 34 psi all around, i'm granny shifting at 3k i had a lot of other car and it's the only one i cant have good milleage out of it. i dont have scan gauge just an obd2 reader.

 

yeah i find shifting at 2k lugs the engine too much unless you are going downhill, I hit vtec a couple of times on the way to work and still managed 35 mpg US (6.5L/100km) and that's idling in macdonalds getting a coffee!

Probably just you're tire setup, I'm on 14 inch steeles all seasons

are you doing any hypermiling at all? engine off coasting and all that jazz?

 

i dont do nothing. i start the car, go to MCD for coffee too and off to work.
no sure what is wrong. Right now, i'm at half tank and only done 190 kms.
no check engine light, no stored codes, no pending codes.

 

I have an AT and best I did was 6.3l/100km (38mpg) all hwy between 100-120km/hr. City i get about 9/100km (26mpg) if its all short trips with lots of idling as there are lots of hills in my hometown.

I bought the fit for fuel economy (AT was what was available) and was really on the fence between it and a TDI but the reliability and diesel cost kind of made my decision.

I find the cold weather is killing me though. Even before I swapped on the winters at 8lbs heavier I found cold air made a huge impact. The heavier rims/tires and cold air combined are surprisingly bad.

 

boucivicisir invest in a odbII reader with bluetooth, there are a lot of nice ones on the market for around 70 usd, worth the investment espically for reading future check engine light codes!

kronk go to rona and buy those foam pipe thingys for $2.99 cad a piece. Stuff it on ur bottom radiator and thank me later, even in 7 degree C weather, driving on the highway the coolant temp never goes past 80 degree C but i always have the heater on.

The 1.5L just doesn't produces enough heat, IMO just block all the air vents at the bottom and none at the top, but i recommend a odbII reader to keep an eye on temps.

 

I have a obd2 scanner already and there is no codes. Last week I changed the Thermostat and I put in a 85c to replace the 80c ( the oem) heat is way better. I put a cardboard in front of the rad also. Cruising temperature is 83+\- I happy with that. L/100 is better now at 9.0 l/100kms. I got ahold of two used but in good condition o2 sensors (oem) that I will be installing next weekend. I'll keep you posted.