Hey everyone I am hoping someone can give me a couple ideas to check with an issue I am having with my LS. About a month ago my car started to get much less MPG. In the summer the car got excellent mileage, 28-30 around town and 32-36 on the highway, in fact I drove all the way from western Massachusetts to eastern Tennessee and got 36mpg the whole way. Right now my car is down to 24mpg around town and 29mpg on the highway, I am getting about 280 miles out of a full tank (11.6 gallons). At first I thought the ECU must be inaccurate so I calculated it myself and it is correct.

My mods are: injen cold air intake (just set up as a short ram), megan racing exhaust, eibach lowering springs. I am back to my old stock tires and rims.

Only thing that has changed is my route to work but, since it is only a mile more each way and has significantly less stop and go I cannot see this being a big factor. Tires are properly inflated as well. Oh and I don't drive like an ass either, only time I rapidly accelerate is when I am passing someone which is not very often. I actually drive better than I did when the car was getting 28-30.

I brought the car to the dealership for routine oil change cause I am lazy and had them check it out for me, the second they saw the intake and exhaust they blamed it on one of them. yet these mods have been on the car since early summer and I haven't had an issue with it.

Anyone got some ideas of things I can check or things that would cause such a rapid loss of MPG? Any help is much appreciated.

 

It is winter. You get worse mileage due to temperature and the gasoline that is used. It's okay, nothing is wrong. I'm sorry for the low mileage

 

winter gas plays a role. try cleaning the filter, this past summer i was down to 23-24 and was getting pissed. i cleaned the filter and ut came back to 27 or 28 on the next tank.

 

like said, it's the winter blend of fuel.

 

Yeah I had thought that but then I thought 4mpg was a bit extreme just from fuel. Well I will clean the filter and see if that helps. Thanks guys, good to know the balt isn't broken.

 

I went from 30-31 avg to 27-28. So it's all good.

 

i'm down about 4-5mpg myself
it happened literally overnight

 

Mine drops every winter by several MPG; its due to longer warmups in the driveway and the computer seems to keep the RPMs up while driving until its all warmed up.

 

Yep, totally normal. My summer MPG is around 27 - 29. Winter MPG is around 24 - 26.

 

Cold oil in the tranny and engine, cold grease in the wheel bearings, pushing your way through 6" of snow, "winter" gas.....should see what happens when the temps start dropping to -35 over night

Was getting 6.9 - 7.1 l/100 km, down to 8.8 on the last tank but not unexpected.

 

Tire pressure it loses about 1 psi per month, the way you drive also lowers MPG if nailing it, stop and go driving as well