Uhhh...something fishy here...

[chaosdrifter06]

I fueled up for the second time today after driving my Festy and fuelly says I'm doing...16.0 miles per gallon!?

Judging from being a 4 cylinder, something would really have to be BAD to make the mileage that bad. If you haven't noticed, it should be updated on my signature. I know I should give it another fuel-up because maybe 2 fuel-ups wouldn't be enough, but just in case, what could be causing it?

-Underinflated tires?
-Larger wheels?
-The 4.11 gears off the Aspire tranny?

I really can't think of anything else that would severely affect the mileage of a car that supposed to be getting 35-40mpg, but 16mpg is truck mileage.

Could the car be running rich? I have cold started it a few times lately and started driving it without warming it up could that affect mileage by driving the engine cold? Cold weather doesn't make the car start properly, I would have to rev the car to 3K and hold it for a second before it would start idling.

I'm going to perform a tune up soon hopefully that fixes any issues. The previous owner says that the rear brakes are sticking so the dragging could cause that as well. Maybe replacing the rear drums may be the way to go.

Any other potential issues I can look into that may cause this pi$$ poor mileage? I feel like the shame of the Festy community for having such ghastly mileage. We usually take pride in our quick, fun, yet fuel-sipping awesomeness.

In other news, the car passed inspection and tonight my speedo died. Anywhere I can check for the issue? I hit a few potholes during the week so I could have shaken the speed sensor loose. Can you guys tell me what to look for since I'm guessing the sensor plugs into the tranny somewhere?

[hotfordcat]

Did you enter the mileage correctly? That would make a big difference.

[1988festivazoom]

when i first did my b6 swap i was getting 30.5mpg all in town, now im down to 15.5 and i dont know how that is possible bc it dosent smell rich and i try to drive it nice. its frustrating but i gave up on my engine long ago! its still better than my 5mpg truck i last had

[Grey Vw]

You got siphoned!

[25Horseplay]

Are you sure the mileage you are getting is right? You swapped gears in the trans and the speedo is most likey incorrect as far as the mileage goes.

[chaosdrifter06]

How would you guys enter the mileage and how would my odometer be inaccurate?

[crazyrog17]

Odometer and speedometer run off the same cable from the transmission. The cable just snapped (common problem) or came loose somewhere between your transmission and the dash.

To enter the miles into fuelly, I use the Trip reading from the last time that I filled up. If you use the odometer, you don't have the option of skipping the entry of a fill up.

What are your 'getting gas' procedures? Fuelly has instructions, but you have to fill it up to the brim every time you get gas to get decently accurate mpg readings.

[econoaddict]

How would you guys enter the mileage and how would my odometer be inaccurate?

If you have different gears and tire diameter then your speedometer should read incorrectly. You will have to adjust your calculations to reflect the larger diameter and gear ratios.
If you have a GPS then you can see what your actual speed is compared to the speedometer reading and figure out what % your gauge reading is off and adjust the miles driven by that percent.
A larger diameter tire will give you a lower miles driven reading.

[GenevaDirt]

swapping to an Aspire tranny should not have put off his readings but the taller tires sure will. Also pull your oil dipstick and smell it....if it smells like gas then you are running rich. If it just passed emissions I doubt there is anything seriously wrong.....just sounds like your calculating. Maybe since the speedo is not working before it stopped it was not reading things correctly.

[econoaddict]

Sorry, instead of gear ratio I should have put speedometer cable gear in the trans.
When I swapped to an aspire trans my speedo was off, it had a grey gear on the trans end of the cable. I put the white gear from the festy in and speedo was back to correct.

[Biff]

Sorry, instead of gear ratio I should have put speedometer cable gear in the trans.
When I swapped to an aspire trans my speedo was off, it had a grey gear on the trans end of the cable. I put the white gear from the festy in and speedo was back to correct.

I think I read about different speedo gears on here before. Must be the amount of teeth on the gear, but not sure how that works(utilizing two different gears on the same driven gear of the tranmisission?)
I'am curious because I have an Aspire trans I might use some day.

[leapin]

My winter milage always drops big time, not just from cold and winter gas, but because my winter tires are mega tall. Throws everything off.

[1988festivazoom]

If u have the aspire trans, the 185-60-13 nexens are the way to go for an accurate speedo. I have them and the speedo is EXACTLY the same reading as my gps, its literally dead on!

[WmWatt]

You are looking at a margin or error of 50% which is not likely to be due to slightly larger tires, or your odometer would have to be measuring one mile for every two traveled. I'd review the calculations.

[htchbck]

Fix the speedo cable first, then try some more calculations. If they are still off, then maybe there's a problem, but I'm betting the odo is not registering correctly. If you have a GPS with a trip function use that, and hit it and the one on the odo at the same time. Drive 100 miles and see if they are anywhere near the same. Remember that the GPS has to be turned on to rack up mileage. My B6 swaps (both with festiva trans) got between 35-45 MPG depending on whether I was in town or on the road.