Low Gas Mileage

etz bseder · #1 02-27-2007, 06:29 PM

My car has been getting only between 13 and 15 miles to the gallon, and I have just been driving it as a normal person would in the city. I used to get much higher with all of my other cars and even a couple mpg higher a couple months ago.

I have a slightly modified exhaust and a cone filter, and a stage 1 ecutune. As far as I know, there are no leaks, and I am out of things to look at/for.

Any ideas what could be causing my very low mileage?

ShiuludeSVX · #2 02-27-2007, 07:23 PM

When your running at highway speeds, what are your RPM's?
If your running at over 2500rpm at 60, then you might be stuck in 3rd, with no 4th gear.

When you roll from a start, is the car quick to respond, or is it a bit sluggish?
If your slow to jump, then you may have lost 1st gear, and your dragging 3500 lbs until you get over 25mph.

What are your Cold, and Hot Idle RPM's?
If the hot idle is not coming down to about 700rpm then check the TPS, and MAF. High idle {over 1500} on a cold block is waisting fuel already.

My 2pennies.

Quote:

Originally Posted by etz bseder

My car has been getting only between 13 and 15 miles to the gallon, and I have just been driving it as a normal person would in the city. I used to get much higher with all of my other cars and even a couple mpg higher a couple months ago.

I have a slightly modified exhaust and a cone filter, and a stage 1 ecutune. As far as I know, there are no leaks, and I am out of things to look at/for.

Any ideas what could be causing my very low mileage?

ensteele · #3 02-27-2007, 11:18 PM

Are you using regular or premium gas?

NikFu S. · #4 02-28-2007, 12:56 AM

Could just be season/temperature related. Sales stickers state a low of 14 should be expected under certain unstated circumstances.

ShiuludeSVX · #5 02-28-2007, 06:37 AM

Quote:

Originally Posted by NikFu S.

Could just be season/temperature related. Sales stickers state a low of 14 should be expected under certain unstated circumstances.

I'm at the same elevation, and although it is not quite as cold here, the temperatures are being sustained pretty low.

I have noticed a bit of a change in my MPG, but only from 24 to 22mpg under normal driving.

I routinely will get almost 400 miles to a tank that I have only run dry one time. My total miles is about to go over 235000 now.

So, I would have to say there must be something else going on in this case.
Maybe the Octane, but I think it's more mechanical.

etz bseder · #6 02-28-2007, 07:16 AM

I deffinately use premium, but i'm in greeley, so who knows if it really is premium. My car doesn't have a high idle but does get close to 700 as a low hot idle. I have checked for codes and i do occasionally get a O2 sensor code, but that's it.

My car is never sluggish and i should have all gears. I just had my tranny rebuilt.

I'm really running out of ideas. I thought our cars were a bit more efficient than this. My car does have a rough start a lot but I have yet to track down what it is of find someone who could.

Any other ideas out there?

NikFu S. · #7 02-28-2007, 05:56 PM

Quote:

Originally Posted by ShiuludeSVX

I'm at the same elevation, and although it is not quite as cold here, the temperatures are being sustained pretty low.

I have noticed a bit of a change in my MPG, but only from 24 to 22mpg under normal driving.

I routinely will get almost 400 miles to a tank that I have only run dry one time. My total miles is about to go over 235000 now.

So, I would have to say there must be something else going on in this case.
Maybe the Octane, but I think it's more mechanical.

Like I said, unstated ie unspecified conditions. If you are getting more than 20mpg you are doing a lot of long distance tc lock driving. "Normal" city mpg is 17. 14-15 should be expected during the winter.
I'm getting 13 and everything is running pretty tip top.