Rover's Vikingship Your Tripcomputer Rover's Vikingship



I ntroduction.

If you have a 2600 VDP,3500 VDP or Vitesse than you are a owner of a SMITHS Trip Computer. Used sensibly this instrument can be extremely helpful. The information it presents will enable you to benefit by lower fuel consumption and make you a safer driver. It will also monitor your car's performance during a journey and help you watch for changes in the performance.
All readings can he displayed in either Imperial or Metric or Federal units.

What is a Trip Computer?

A trip computer is basically a calculator and display. It takes information on petrol flow and wheel rotation from special sensors, and using its own internal, highly accurate quart, tunebase, it computes and displays digitally the selected information to the driver durinq the journey.

What do you have to do?

All the driver needs to do is to depress the "CLEAR" button for three seconds at the start of a journey. This will reset all the displayed information, other than time and date.
At any time during the journey, information can be displayed by depressing the appropriate button momentarily.
If you enter the expected journey distance before setting off, the trip computer will tell you its estimate of your time of arrival and distance still to go.

What do the various buttons do?

1. TIME and Calendar
Pressing the button once will make the computer display time of day in hours and minutes. A second press shows date and month. After three seconds the display will revert to hours and minutes.

2. EL. TIME (Elapsed Time)
The computer will display the time since the journey began ("CLEAR" button last pressed). This will read in minutes and seconds during the first hour, and then read hours and minutes up to 60 hours.
The last figure changing once per second will tell you when the former is being displayed. Whilst the timer is running, the colon between hours and minutes will flash every second. (See HOLD).

3. E.T.A. (Estimated Time of Arrival)
The computer displays its estimate of the time of arrival at your destination assuming you continue at your current speed. As this requires the expected journey length, you should enter this before leaving as explained in the section "How to set the trip computer". If the E.T.A. for your journey becomes unrealistic, the display shows 0.0. This happens if your E.T.A. would be more than 24 hours from the current time.

4. S.T.P. START (Stopwatch Start/Stop)
This key controls the independent stopwatch. Press once to display the stopwatch time.
The colon pulsates if stopwatch is running, and remains fixed if not. Subsequent presses start and stop the stopwatch. After each hour the stopwatch zeroes and continues to display stopwatch time in MINS SECS. The stopwatch can be zeroed by momentarily pressing "CLEAR" while stopwatch is selected. This operation does not affect other trip data unless ''CLEAR" is pressed for 3 seconds.

5. DIST. (Trip Distance)
The computer will display the distance travelled in miles or kilometres to an accuracy of a tenth of a unit, during the journey, up to 1,000 miles or equivalent kilometres.

6. INST. CONS. (Instantaneous Fuel Consumption)
The computer displays fuel consumpion in miles per gallon (Imperial or Federal) or litres per 100 km (Metric) over the last three seconds. As a consequence of this frequent averaging, the readings will fluctuate widely dependent upon accelerator position, climbing or descending hills etc.

7. AV. CONS. (Average Fuel Consumption)
The computer displays the vehicle's fuel consumption in miles per gallon (Imperial or Federal) or litres per 100 km (Metric) calculated over the journey. NOTE: After 100 Imperial Gallons, or equivalent have been used the computer displays ..0 until "CLEAR'' is pressed.

8. AV. SPEED (Average Speed)
The computer displays the average speed during the journey i.e. total distance travelled divided by total time taken. NOTE: After E.L. TIME exceeds 60 hours, the computer displays ..0, as the average speed will he fairly meaningless by this time.

9. ARR. DIST. (Distance to Arrival)
The computer displays the distance remaining. As this function requires an estimate of the expected journey length, this data should he entered before leaving.

10. HOLD
Pressing this button will cause the computer to display HOLD The information accumulated during the journey will riot be allowed to change until the HOLD button is pressed a second time. If you wish to read any other information whilst the information is held you may do so by pressing the appropriate button. You must however remember that the information cannot be altered further without a second press of "HOLD". The HOLD indicator will stay on, whenever the HOLD function is selected to remind you that your data is frozen. When the ignition is turned on, HOLD is always displayed if HOLD is operative.

11. CLEAR (Trip Clear)
Pressing "CLEAR" for three seconds resets all the trip data to zero. The stopwatch is only affected if this is done while displaying stopwatch.

12. Imperial/Federal/Metric
This three position switch converts the readings between Imperial, Federal and Metric units: Gallons, U.S. Gallons or Litres, Miles or Kilometres.

How to set the Trip Computer

1. How to set the time
Press TIME. Press SET "SET" will be displayed.
Press NN MM, where NN is hours and MM is minutes it 24 hour clock format. The time entered will be displayed.
Press "SET" releasing this key starts the clock from this time.

2. How to set the date
Press TIME twice. Press "SET"-SET will be displayed.
Press DD MM where DD is current date and MM is month. Press 'SET'.
The clock and calendar are now set.

3. How to enter distance to arrival on journey. Before leaving.
Press ARR. DIST.
Press "SET"- SET is displayed.
Press NN MM where NN is the distance expected for the trip.
Press "SET". The distance is now entered, and ARR. DIST. and E.T.A. will he operational. The ARR. DIST. may be updated at any point by re-entering the new value.
NOTE: If invalid data is entered, the computer will ignore it and display SL T to tell you to re-enter it.

How do you save money?

1. Unless you are already an expert driver it is likely that your driving technique uses more fuel than is necessary. Therefore your first test should be to evaluate the average fuel economy over a typical journey.

2. PRESS CLEAR FOR THREE SECONDS AND THEN AV. CONS: Drive to work in your normal manner and watch the trip computer reading. After about one mile the reading will start, fairly low (you have a cold engine and probably the choke is out) and then gradually read higher.
If the journey is very short press 'HOLD' whilst you are at work, and again press 'HOLD' again when you restart your journey. This can be repeated if necessary on consecutive tourneys.
NOTE the reading after you have travelled say 100 miles.
The time, trip time, trip distance and average speed, and stopwatch are also available by pressing the appropriate buttons. Also estimated time of arrival and distance to arrival can be displayed, if you entered AR R. DIST. before leaving.

3. PRESS CLEAR for 3 seconds again and drive in the following manner:
a. Replace the choke as soon as possible.
b. Try to conserve momentum i.e. think ahead and accelerate and brake only slowly.
c. Try to be light footed i.e. at your chosen speed release the accelerator slightly at every opportunity.
d. Keep your foot off the accelerator whilst in stationary traffic.
e. Do not exceed 70 mph on motorways and travel slower than this, say 55 mph to 60 mph, if at all possible.
f. Avoid single short trips, whenever possible.
By using these techniques which are not new, and observing the continuous average fuel consumption, and trying to maximise the reading over the next 100 miles, you should show an improvement of between 5% and to dependent upon your particular average journey and previous driving habits.

4. The INST. CONS. or instantaneous fuel consumption reading is most useful at the higher rates of consumption.
You will be surprised to see the difference at 50 mph between putting your foot hard down to accelerate, and lifting it off to brake the vehicle. Remember you must wait three seconds under each condition for a reading.
If several consecutive readings of INST. CONS. are below the AVE. CONS. figure, then you will be reducing your average and if above you will be improving your average.

5. NOTE: a 10% improvement in fuel economy can save you approximately [60 every 10,000 miles, at current prices.

Why are you safer ?

Encouragement to drive in the manner described will make you a better and safer driver.

What else Can you use the Trip Computer for ?

1 Profile of your car on a straight, flat piece of road travel at a constant 30 mph in top gear.
Press 'CLEAR' for three seconds and hold the speed as constant as possible for about 5 minutes using the E.L. TIME reading. Then press 'HOLD' to freeze this information until you can conveniently stop to write down the AV. CONS. figure, or your passenger can do this for you.
Repeat this exercise for 40, 50 and 70 mph. You will now have an idea of the fuel economy of your vehicle at these constant speeds, and will he able to assess the effect on fuel economy as you increase speed. The figures will he quite high as they represent constant speed conditions something you should always strive to achieve, where road conditions permit.

2. Trip distance readings are easier to read than the small speedometer odometer figures, and can he in miles or kilometres.

3. AV. SPEED can he useful when travel journeys include a combination of motorway, town and country driving.

4. E.T.A. is particularly useful on longer journeys, and motorways where you often at consistent speeds.
It will continuously its estimate of the time of arrival at your destination, allowing you to slow clown until an acceptable arrival time is indicated. By driving at less than the maximum speed possible, as dictated by road conditions, you save fuel, and so money.
Provided the journey distance was entered correctly, E.T.A. will adjust itself so that when distance to arrival is zero, your E.T.A. is the current time.
While the computer cannot be aware of possible traffic obstructions in the later part of your journey, you can often allow for these when interpreting the E.T.A. reading.

5. The distance to arrival function shows you precisely how far you still have to go. This can he Used with the fuel gauge to check you have enough fuel left to complete the journey.

6. 6. Stopwatch can be used to time events to the nearest second, without affecting other trip data.

How accurate is the Trip Computer ?

Time measurement is accurate +1 second in 24 hours. Distance' measurement is normally within 2% dependent upon tyre wear and pressure. Fuel flow measurement accuracy depends on fuel temperature, air bubbles, carburettor performance and speed, and the overall error is within 5%

Summary

If you really use your trip computer - if you begin to Understand the poor fuel economy of a short trip, or a heavy foot on this accelerator pedal then you will find your computer very valuable.
Leaving it primarily on average fuel consumption and resetting it regularly between trips, will he a constant reminder for you to maximise the reading.
You will now subconsciously apply a better driving technique, he aware of other vehicles around you, of uphill and downhill gradients not noticed before, and you won't visit the petrol pump quite so often.

 



 

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© rwp aug 2003