fuel gauge and miles remaining - 986 Forum - The Community for Porsche Boxster & Cayman Owners

ohhh my · 10-02-2013, 12:01 AM

About a month ago, my fuel gauge would only read up to 3/4 tank but the tank was surely full due to a little overfillage at the pump and following pumps would equate to approximately how many miles I had used on on that tank.

I found a little trick to get the needle to go all the way to full. The trick is to have the ignition in the on position (with engine off of course) while pumping gas and this led to a full tank of gas reading.

This last tank, I did ALL city driving and when I went to pump gas today, it read full but the miles remaining was around 210, which is what I got on my all city driving on my previous tank.

In the past, it would usually read 300+ does the computer base the milage remaining based upon your previous fill up? I'm assuming no? I'm assuming the computer just has a read out of milage remaining based upon the amount of fuel in tank. Am I correct? Any reason why I pumped 15 gallons today(ran it really low due to a busy schedule) but the milage remaining is only at 210?

jb92563 · 10-02-2013, 05:51 AM

I think the computer is using the MPG average to calculate how many miles are left, so if you were driving "spirited" the MPG were low, as would the remaining miles on the tank at that time.

Try resetting your MPG and then see if the Miles remaining look much better after some gentler driving.

Also parking on level ground may get you a better estimate.

What yr/model do you have? I've never had that issue with my '01 S'

ohhh my · 10-02-2013, 05:56 AM

I have an 03 so I always reset all after each fill up. I'll try resetting it right before my next fill up and coast into the station with a high average mpg and see if that makes a difference. Haha.

But on the contrary, I remember in the past it was always in 300+ range regardless of what I averaged. Hmmmm

SeanZ4 · 10-02-2013, 06:41 AM

My '00S does the same thing. (only reads 3/4 full when actually full) I read somewhere to do the exact opposite. (take the key out completely when filling) It didn't work so I'll try your way. I'll try to do that today/tonight and report back my results!