Gas mileage dropping in winter?
01-06-2006, 08:42 PM
#22
Senior Member
SL Member
Join Date: Sep 2005
Location: Middletown, CT
Posts: 230
I don't know if its the same with all Scions, but in my TC during the winter, I notice my transmission (automatic) hangs on to a lower gear so that my engine stays above 3000 rpm so that it warms up faster. Once the engine is sufficiently warmed up, the transmission returns to normal. So it burns more gas since it is revving so high for a period of time.
01-06-2006, 09:47 PM
#23
Junior Member
Join Date: Jan 2006
Location: eastern Ontario
Posts: 1
hi folks -
found my way to this forum from my web logs as a result of the link to my site posted above. (i'm the guy who originally put together that list of reasons why winter MPG is often much worse than summer - i guess i'm the 'metro a$$clown'... ;) )
anyway, thought i'd pop in on this one:
the previous poster was right, in that it's controlled by the ECU. but the ECU controls this "feature" based on engine temp, and if you had some electrical knowledge, you could spoof the engine temperature signal to fool the ECU into permitting overdrive sooner. it would involve adding resistance to the coolant sensor return wire. so theoretically, yup, you could do it.
the downside is that approach would affect other variables that the ECU is controlling from the coolant temperature signal, such as air/fuel mixture (it's richer when cold). that could hurt driveability before the engine actually warms up though (e.g. poor responsiveness, or worst case, stalling out).
the best compromise would be to actually try to help the engine warm up faster, by:
- using a block heater
- installing a winter time radiator block to reduce air flow into the engine bay / radiator. (this is a common tactic used by honda insight owners whose cars won't go into lean burn mode until the engine is warm enough - google insight radiator block for more info. but be careful you don't block too much or you could overheat.
- setting up a "warm air intake", also a common insight mod (google it here). this mod will help with engine temp and MPG, but it will also reduce power slightly (opposite effect of a cold air intake).
just some ideas.
cheers.
(obviously i'm not a scion owner, but i think an xa would be pretty cool! we don't get the scion brand in canada, but have had the echo/yaris hatchback for 3 or 4 years here.)
www.MetroMPG.com
found my way to this forum from my web logs as a result of the link to my site posted above. (i'm the guy who originally put together that list of reasons why winter MPG is often much worse than summer - i guess i'm the 'metro a$$clown'... ;) )
anyway, thought i'd pop in on this one:
Originally Posted by dchichaz
Does anyone know if there is a way to stop this from happening? I want the engine to shift like normal even when it's cold.
the downside is that approach would affect other variables that the ECU is controlling from the coolant temperature signal, such as air/fuel mixture (it's richer when cold). that could hurt driveability before the engine actually warms up though (e.g. poor responsiveness, or worst case, stalling out).
the best compromise would be to actually try to help the engine warm up faster, by:
- using a block heater
- installing a winter time radiator block to reduce air flow into the engine bay / radiator. (this is a common tactic used by honda insight owners whose cars won't go into lean burn mode until the engine is warm enough - google insight radiator block for more info. but be careful you don't block too much or you could overheat.
- setting up a "warm air intake", also a common insight mod (google it here). this mod will help with engine temp and MPG, but it will also reduce power slightly (opposite effect of a cold air intake).
just some ideas.
cheers.
(obviously i'm not a scion owner, but i think an xa would be pretty cool! we don't get the scion brand in canada, but have had the echo/yaris hatchback for 3 or 4 years here.)
www.MetroMPG.com
Thread
Thread Starter
Forum
Replies
Last Post
evolving_machine
Scion tC 2G Drivetrain & Power
17
10-21-2023 01:16 PM
Fisqual
Scion xA/xB 1st-Gen Drivetrain & Power
3
09-22-2015 05:51 AM
