Jetdriver69

I thought my son's 82 5 speed was getting very poor mileage until I measured it manually. For exactly half a tank, 11.35 gallons he is getting right at 14 mpg in city driving.

That is, a 16 year old driving a 5 speed to his girlfriends house, to school and goofing around. So lots of accelerations and stopping.

I see about 22ish on the highway at 75 mph. Of course this a brand new engine with zero vacuum leaks

These numbers pretty much match factory estimates but are these numbers about what I can expect for a well tuned 4.5?

marine928

I average around 24 hwy using cruise control 70% @ 73 mph.
Around Houston light pedal ( except occasional yellow light) 17. If I were 16 and driving a 928 I would probable get better mileage since I would be parked most of the time utilizing the fold down rear seats to explore the female anatomy...

ThetaTau87

I have averaged 18.2 overall in mixed driving with my 89 5-speed in mixed driving. About 50/50 highway and city.

Jetdriver69

LOL! Unfortunately the hatchback is completely full with a monster amp, two 6X9s and Kicker subwoofer. So he just goes to her house for the anatomy lesson.

NickT

I get 19 to 20 if I am good..

Alan

Around town - lots of short trips I get about 14MPG average - with enthusiastic driving much of the time.

Best case is about 22-23MPG on the highway at legal-ish speeds.

Alan

The Forgotten On

I get round 15 in the city and about 20 on the highway.

I have a 3 speed slushbox in my 81, and driving it since I was 16 hasn't helped get better fuel economy along with the extra fat tires I have on it from a Panamera.

I did get 2 mpg better with my old tires and wheels in the city, 215 vs 265 makes a difference.

Along with trying to not engage the fuel enrichment. But the Bwahhh is just too tempting , especially with most of my interior removed.

I still need to fix a few vacuum leaks though so I should see an improvement. I am normally running regular unleaded 87 octane with the occasional tank of 91.

chitown928s4

MPG should never be discussed when owning these cars. We didnt not buy them because their good on gas but because they are beasts.

The Forgotten On

It tells you when you have a problem or not on the car and if it is running correctly.

brealytrent

ugh...

vanster

I get around 14 around town and about 19 on long hwy drives, like SF to LA. I keep track of my fill ups using an app to monitor how it's running. The window sticker says 15mph so I guess it's about right