gbarron

I use Fuelly as well to track MPG. My average overall is 19.4 MPG (tracking since 2012) and my best was 23 MPG (using the cruise control on the I-5 during a trip to Cali).

DKWalser

I don't have a break-out of city and highway mpg. Overall, I've averaged 16.11 mpg. My best tankful was 17.50 and my worst was 12.00.

Sounds like I'm getting worse mileage than the rest of you. Most of my driving is during rush hour. There's a lot of starting and stopping, with occasional stretches where traffic is moving at 70 mph (or more).

Mongo

I got 13 around town in my S4, and about 21-24 on the highway doing 75mph. Seems this car does better at speeds above 65.

GlenL

I'll use 7 gallons in 30 minutes while covering about 45 miles at the track. That's 6.5mpg.

I recall getting about 14 mpg in city driving.

Wisconsin Joe

For typical driving (mix of city, 2 lane highway & freeway) about 17.

Roadtrips on the freeway (75-85 mph) about 21.

Behaving myself on the freeway (under 70) I've seen almost 23.

MFranke

Average 20, consistently with mix of city, suburb and highway with Atlanta traffic

auzivision

I can get mine down under 10MPG, sometimes as low as 7 if I'm really having fun. Someday, I hope I can get down to under 6.

Ricardo Vega

Sounds like a broad range. For those who are getting higher MPG's, what modifications have you guys done?

What additional mods can one make to improve? Better headers? Exhaust system? Porting heads out? Higher tire pressures?

Ricardo Vega

ThetaTau87

Driving technique is the biggest factor. The main key is keep time spent accelerating to a minimum. That means accelerate quickly to your desired speed then use as little throttle to maintain speed. Yes, accelerating quickly is actually fuel efficient. As long as you don't over accelerate.

Leave a gap to the car ahead so you can coast rather than brake if they slow. As soon as you see a light turn yellow let off the gas and coast.

When accelerating keep the engine near the torque peak. When cruising use the highest gear possible without bogging the engine. This means you will probably need to downshift to accelerate.

All these things together will significantly improve fuel economy more than any mods. A chip tune will improve efficiency due to increased torque as long as you don't just use the extra power to rip around and waste fuel needlessly accelerating.

Driving like a grandma with long slow acceleration is horrible for fuel economy. Accelerate quick and get off the gas.

dr bob

My first car, a 1965 356SC cab, came with the instruction to "accelerate briskly and get into top gear as soon as possible" to get the best fuel economy. It works.

MFranke

This is great. I accelerate all the time, while laying back in my seat with the steering hub extension. Still get 20 mpg. Good to hear the fun is not causing missing mpg.

V2Rocket

if you have an AFM car, past a certain RPM at WOT (which motronic tends to understand is past 60% throttle) the ECU is just "guessing" at fuel quantity to get its target AFR, because the flapper door is stuck fully open and isn't measuring anything anymore. a lot rich is safer than a little lean so...

i imagine the CIS cars are similar. MAF stuff is mostly exempt from this.

nice thing is that the 2-valve head seems to like it rich...down into the ~12.6:1 range it keeps making more power.

moral of the story...stay out of the go-pedal for mpg

OTR18WHEELER

Don't know much ' bout all that fancy math stuff, but I get 80 miles per 4.5 gallons of 93 octane, interstate at a little bit of 70, and a little bit more of WOT here and there.
I figure 19mpg and call it even.

safulop

I do 12-13 mpg in all-city conditions, but it varies by gasoline formulation and season. I get 20 easily on highway, as high as 23 mpg at 80 mph. The mileage can vary considerably if your MAF is not brand new and if you have performance chips installed.

heinrich

16mpg on a healthy S4 manual in town. Down to 12 if you're in an auto and driving short trips. Long road, up to 24pmg in a healthy manual S4.