The last 2 fill-ups, I've been averaging about 14-15 MPG. I usually average about 18-19, which I thought was low as it is, since I hardly drive the car hard. I drive about 50/50 (city/highway), I rarely hit 10+ PSI (maybe like 3 times a day), normally shift around 3-4K rpm's.
Mods are: TBE w/ HFC, Intake, MBC @ 23PSI, 255 FP, and Dyno Tuned by Sean Ivey.
I was thinking maybe an exhaust leak, but any other things I should be looking for? Any input would be greatly appreciated. Thanks in advance.

 

It could could possibly be the winter blend of fuel being used. I have noticed a a fair drop in my gas mileage this season from the previous high 20's mpg I was getting. It also may also be a lead foot as well and you just not noticed.

 

I definately don't have a lead foot, I wouldn't have started this thread if that was the case. Like I stated above, I really don't drive the car hard to be getting this kind of MPG. Thanks for the input though .

 

what's your tire pressure look like? tire pressure has a huge impact on mileage. Tire pressure also decreases with drop in temperature.

 

Tire pressures are at 33/30 on stock size Toyo Proxes 4's. I did have it at around 37/34 about a month ago. I will try and up the pressure again and see if that helps. Thanks for the input .

 

My mileage went down the craper lately as well. Could it be this unusually cold weather, i dont know. Typically i can acheive 20 mpg average, last two fill ups i'm under 15 as well. Car is bone stock and I have not changed my driving habits...

 

Squeeze don't Mash young lotus

 

weather.

 

also how many miles on ur 9? r u using leaded race gas? the winter gas should be alil worse for mpg but not in such a huge margin... i'd swap out the o2 for good measure and maybe see if u can clean ur maf even

 

I have about 14.5K miles on my 9 and never used race gas. Wouldn't a CEL come up if my O2 sensor is bad?

 

I would guess it's the cold weather you guys are getting. Car is stuck in cold start/warm-up mode longer.

 

I noticed this myself, so I talked with a local shop and they told me its a combination of the winter gas and the cold weather, he told me not to worry, when it warms up everything will be normal. I tought this was wierd having never been in a "cold" weather state, but hey, what you gonna do, drive slower

 

Well, how long is your commute? If it's a short commute, it's definitely the cold start-ups and the delayed obtainment of an optimal operating temperature.

 

My commute is about 16 miles each way. And I usually don't get any traffic to/from work.

 

Same here, I am averaging about 15 mpg the last few months also