Terrible MPG? - Maintenance and Repair Forum

Forum Post / Reply
You must log in before you can post or reply to messages.
Terrible MPG?
Friday, December 22, 2017 3:31 PM
I am getting ridiculous MPG right now, close to 20-22 with most of my mileage being highway miles. No stored codes, no CEL. I deliver pizza in this car, so lots of stop and go, but my commute is 25 miles one way. I've tried premium ethanol free, regular 87, etc. Result is the same. Any insight on wtf is going on here? List of things done in the last year:

-New iridium spark plugs
-New coil-on-plug pack and ignition module
-New CKP
-Cleaned air filter on cold air intake (stuck inside engine bay)
-New Fuel Pressure Regulator
-New Fuel Pump
-New Fuel Filter
-Tires bought in March of this year, properly inflated on 18" wheels
-Up-to-date oil changes with Royal Purple 5w30
-New brakes all the way around (rear disc conversion)

Modifications include:
-Full Body Kit
-Fast and Furious Wing
-M3 mirrors
-Shift Kit (off) 4T40e
-Rear disc brakes, saturn/neon
-18" wheels and tires, aluminum lug nuts
-2.5" headerback exhaust including Pacesetter Header, OE o2 sensor, Magnaflow hi-flow cat

That's all I can think of that could be causing any kind of terrible fuel mileage. Any thoughts?

Re: Terrible MPG?
Saturday, December 23, 2017 7:47 PM
that seems pretty low for an eco powered car. any signs of it running rich?



Re: Terrible MPG?
Saturday, December 23, 2017 9:47 PM
Not that I can tell, no. It seems to burn pretty clean. It starts up awesome, idles awesome, good power... So... ???
I have yet to check PID though.
Re: Terrible MPG?
Saturday, February 24, 2018 7:50 AM
if you fuel trim is in spec, its probably not engine related.

premium fuel won't make any difference on a base engine. unless your running a high compression engine or boosted.

it that number really that bad for 100% stop and go in the winter?

my 05 eco got best 47mpg imperial gallon highway but was half that when driving like your conditions in the winter, warming it up. short trip shut it off etc. I didn't have a body kit...extra weight and drag.

take it for a highway only test drive and see what your getting. If the number is normal...its gotta be all the stop and go.
Re: Terrible MPG?
Sunday, February 25, 2018 7:13 PM
Not trying to be smart, but have you checked your tire pressure? Low tires cause terrible gas mileage. I actually run approx 1-2 pounds over recommended in all 4 the get maximum gas mileage I can.




Ipud wrote:

We put Jap Traps on cinder blocks around here. We don't wave the American flag for novelty


I proudly own American cars, nothing else....



Re: Terrible MPG?
Sunday, February 25, 2018 7:23 PM
Oh crap never mind. I didn't get all the way down the list to see you bought new tires.



Ipud wrote:

We put Jap Traps on cinder blocks around here. We don't wave the American flag for novelty


I proudly own American cars, nothing else....



Re: Terrible MPG?
Monday, February 26, 2018 6:07 PM
What is your elevation?




On the inside my car looks like a fighter jet.
Re: Terrible MPG?
Tuesday, February 27, 2018 10:44 AM
Stop and go on winter blend fuel and automatic trans is a killer for MPG. On the highway, your aero is killing you. Someone else mentioned fuel trims. Log them and see what you get. If they're high in either direction or don't fluctuate well get a new upstream o2 sensor. I'd bet those heavy 18s aren't helping either.



"In Oldskool we trust"
Forum Post / Reply
You must log in before you can post or reply to messages.

 

Start New Topic Advanced Search