Audi Loyalist

in the land of the Canuck?

ryanrS4

thats about what i get...maybe 1 or 2 mpg better... 9k miles btw 2.0T quattro mt6

DeMOROlized

But we smart Canucks usually convert to US mpg for your reading pleasure. ;-)

Audi Loyalist

especially towards your enthnocentric neighbors to the south

quattshot

If your cruising and you are not accelerating AT ALL, then throw it in 6th. It doesn't matter what your speed is. You can be doing 25mph in 6th gear. The RPMs are SUPER low and your burning less gas.

J.

P-Nasty

i drive 30 miles to work, and i live right by the exit and work 2 blocks off the exit. Sometimes I ge to work with 35 miles per gallon. I think it helps when im right behind a car and draft them a little.

I try not to because of rock chips, but Cali freeways are a joke and sometimes you cant help it.

JimFerraro

<center><img src="http://pictureposter.audiworld.com/99826/map_example.jpg"></center><p>
Obviously, you do not have a background in live dynotuning and tuning vehicles from scratch with or without menu driven software.

Fortunetely, I do.

Please accept my apologies in advance if any of this is taken the wrong way.
I'm not trying to be assy here, but I'm going to put someone in their place when they don't know what they are talking about.

Load is unique in all gears, all speeds, its affected by # of passengers, fuel in tank, wind, temperature, tire inflation.
Load is unique in every situation, not only when accelerating, but while cruising too.

Calculated engine load is directly related to VE and is part of the main calculation for fuel consumption. RPM is secondary and has a less dramatic effect.

Lets take a look (above)at a typical fuel map, doesn't matter what car. For simplification, I'll show the commanded air fuel ratio for each load/RPM.
x axis = RPM
y = Calculated engine load

Take note, air fuel ratio (or commanded air fuel ratio) varies much mroe by load then it does RPM.

So now we'll pose a very common scenario:
Pick any vehicle,doesn't have to be an Audi. Lets say you are running at a steady 40 MPH in 5th gear at 2000 RPM and 70% calculated engine load.
If you drop to 4th gear and run 2800 RPM at 50% calculated engine load, you will get better mileage.

I've tested this scenario live many times on a lot of different vehicles, even with test equipment that shows "actual live mileage", real time.

Take a look at the map, and remember this is only one example of many different fuel maps.

You'll notice the AFR fattens up with LOAD, not so much RPM.

Increased load requires more fuel, so very often, a higher RPM will actualyl increase your mileage, so long a lower load can be attained.

I could keep going here, but I'm out of time, lol.

JimFerraro

Not necessarily.

For most cruising situations, 5th or 6th is ok in these cars. That is, if they aren't lugging, or unless you're only going 40 MPH.
I'm usually in 4th, at most 5th at 40-50 MPH....and 5th is only used when I know I'll be at the steady speed for quite some time.

The car only sees 6th gear on the highway, or when at a steady 65+ in a non-traffic situation.

I regularly get a true hand-calculated 29-31 MPG combined.

JimFerraro

The comments I posted are certainly not "absolute' in all circumstances.

There are a thousand variables that affect fuel consumption, and every vehicle has different gear/rpm/mph mileage sweet spots.

I have NOT tested the A4, other than hand calculating mileage.
However, there are trends in mileage testing that tend to work across the board.

Moderate RPM and low load is better for mileage than low rpm and high load.

dawnj

Thanks for the info everyone. I have an automatic transmission. I will watch the braking (the grab still takes me by surprise) and see if things get better by 5k.