What do you set the middle display to most of the time (I believe the middle is only one that keeps the selection when you turn off the car)?

I mostly have mine set to outside temp, watch instant fuel rate some of the time, once in a while check distance to empty. Not sure the point of average speed or average fuel rate, these never change unless I go on a trip and then after a while they change very slightly.

And here's a dash trivia question ... what's the interesting difference between how instant fuel rate appears in "MPG" and "L/100 KM"?

 

I generally leave mine on MPG. It's an instant read on how the car is running. In the summer sometimes it's on outside temp.

When reading MPG, a higher reading is more desirable. For L/100 KM, the units are different and the reading is inverted, so a lower reading is more desirable.

 

Usually Temp. When I drive it to work on occasion I like to watch it go from 65F +/- work to my home 45 miles away 105F+/- during the summer months..... I know I need to get a life...

'89 S4 GP White/Black
'76 912E Silver/Black sunroof

 

Wow, really? Sorry, I just couldn't resist and I know we have people here used to L/100 KM I just had to be a smart a$$.

Really, I am a nice guy, well maybe not but I think I am.

 

You're supposed to reset those every time you fill up with gas, like you reset the odometer. That way, you can do your own calculation of how far you can go based on the size of your tank and the average MPG. If you just let them go without resetting, they will become static numbers that mean little.

Dan
'91 928GT S/C 475hp/460lb.ft

 

I normally keep my dash settings on instant MPG except when I get low on fuel. I then change it to remaining miles just so I don't screw up too bad.

 

I leave mine on distance to empty all the time. I reset the avg speed and avg fuel consumption and trip meter every time I fuel up.

 

I have noted that when I turn the ignition off and restart the trip meter always returns to Odometer I.

When I drive I usually have the dash computer set to average Litres per 100km to watch how the engine is running.

Interesting to note the change consumption when city driving and hard acceleration and watch the consumption climb.

Sometimes I have it on instant fuel rate, again to gauge how the engine is running.

If I on a trip I will start the stop watch and leave it running in the background to gauge the time taken on a long trip.

When I fill up with fuel, I reset the average fuel consumption per 100km, I reset the odometer 1 and II to zero, however on a trip I will leave odometer II running for the trip to check the total kilometres travelled to have the total distance and then work out the overall fuel consumption rate per 100km. I note the distance travelled by odometer I as a kilometer reference between fills.

At each fill I record the quantity of fuel to fill and then calculate the rate per 100km, as an accurate fuel consumption rate and the cost of fuel to fill and the cost per litre. This allows me the check the average fuel consumption rate for trips and city driving over a 10 year period. If the average fuel consumption rate climbs then I start searching for the "WHY"

From this I can gauge the fuel consumption at a set speed and compare it back to the fuel graph in the owner operation manual to check on how the engine/car is performing and whether is it performing to the design specifications.

When I'm on a long trip I use the log system on my GPS for elapsed time for the trip and the actual driving time, so can sit on the correct speed limit with the cruise control, get the average speed for the trip and the overall average fuel consumption. The GPS as indicated the my speed indication is 8km/hour low at 100kms/hour.

I use the outside temperature setting on a hot day to gauge the effective opertation of the A/C and it was interesting to note recenty on a 39 degree C day with 3 adults in the car in city stop start traffic the cabin temperature was climbing, however the engine temperature remained constant under 90 deg C as both electric cooling fans were working a full speed. My A/C operate efficiently on a trip especially with only me on board.

I also check when I have exceed 1500 rpm in a downhill run and then go to coast, with the foot off the accelerator pedal that the instant fuel consumption return to zero.

If you are rally driving you can use the stop watch for point to point times etc.

From the above, you can gauge how the digital dash can supply you with excellent and very useful information.

Tails 1990 928S4 Auto

 

Outside temperature here. Sometimes I pull the stalk twice to switch this to Celsius, as Fahrenheit is still not as meaningful to me.

On the left display, I always switch it to speed. I never look at the actual gauge - I always read my speed from the digital display. Faster and more precise.

 

After 28 years in Canada I'm somewhat used to Celsius, Kg and Km but L/100km is just out there.

When I drive a 928 with digi dash I like to see outside temp (so I know I'm pushing tyres beyond there limit) and MPG..............stuck between imperial and metric

 

I use all of them from time to time.. for regular driving, I tend to leave it on range remaining, mostly to avoid that horrendous red "Call Range" warning from popping up.

I also use instant and average fuel economy when driving around town, as these days its too congested to drive fast, so I made driving economically my game to keep me amused.

 

I use the optional BWAAAAAAAA factor for the read out. 8>)
Temperature most of the time.

Another owner stuck somewhere between metric and imperial.
I was totally changed to metric and then I moved to the States.

 

Dr Bob had the answer to the trivia question (sorta) ... the interesting thing about the instant fuel rate is that in L/100km, when the injectors shut off, the display goes to zero.

In MPG mode, the display goes to 90 with the injectors off ... cannot show "infinite" which would be the more correct analog to zero units per distance.

 

Ok...

I drive the car up the mountain to my cabin and back. It's all uphill, but I still manage to squeeze 16 miles from a gallon on the way up. On the way back, it reads 60 MPG all the way home. What is my mileage for the trip?

 

33 mpg overall for that trip if you took the same roads up and down and it was an actual 16 mpg up hill overall average and a 60 mpg downhill average.