Toyota uses 4 liters of petrol per 100 km,and audi 12 liters per km. Both cars are racing on 25 km distance. How much did they use together

800km it wiil take

best at 10 liters per 100 klms , average around 12 liters /100 klms
fuel consumption depends largely on load , speed , operating conditions , towing, highway/city, off road so an exacting answer is not possible as it all depends on the operator and the driving skills

Have you changed the plugs, changed the air filter, etc. Many times a clogged air filter will kill the mileage. Have you had a compression test to see if it is just wore out? All sorts of things need to be checked to answer this.

8 km per litre, or 12.5 litres/100km is certainly a bit heavy for that model, but not disastrously so, as in city driving it was rated at 10 L/100 km when new by Govt agencies where I am in Aust.

So the usual suspects in an older car are

- dirty air filter
- low tire pressures
- spark plugs worn or fouled
- ignition timing incorrect
- fuel pressure too high
- fuel injectors worn
- evap canister filter blocked
- emissions system faulty (EGR valve or Vacuum Switching Valve)

It depends on the distance, the speed at which you travel, the efficiency of the engine. Use the average mpg of the car on highways, and the length of the trip.

The following are examples of expressions:
2
x
3 + 7
2 × y + 5
2 + 6 × (4 - 2)
z + 3 × (8 - z)
Example:
Roland weighs 70 kilograms, and Mark weighs k kilograms. Write an expression for their combined weight. The combined weight in kilograms of these two people is the sum of their weights, which is 70 + k.
Example:
A car travels down the freeway at 55 kilometers per hour. Write an expression for the distance the car will have traveled after h hours. Distance equals rate times time, so the distance traveled is equal to 55 × h..
Example:
There are 2000 liters of water in a swimming pool. Water is filling the pool at the rate of 100 liters per minute. Write an expression for the amount of water, in liters, in the swimming pool after m minutes. The amount of water added to the pool after m minutes will be 100 liters per minute times m, or 100 × m. Since we started with 2000 liters of water in the pool, we add this to the amount of water added to the pool to get the expression 100 × m + 2000.
To evaluate an expression at some number means we replace a variable in an expression with the number, and simplify the expression.
Example:
Evaluate the expression 4 × z + 12 when z = 15.
We replace each occurrence of z with the number 15, and simplify using the usual rules: parentheses first, then exponents, multiplication and division, then addition and subtraction.
4 × z + 12 becomes
4 × 15 + 12 =
60 + 12 =
72
Example:
Evaluate the expression (1 + z) × 2 + 12 ÷ 3 - z when z = 4.
We replace each occurrence of z with the number 4, and simplify using the usual rules: parentheses first, then exponents, multiplication and division, then addition and subtraction.
(1 + z) × 2 + 12 ÷ 3 - z becomes
(1 + 4) × 2 + 12 ÷ 3 - 4 =
5 × 2 + 12 ÷ 3 - 4 =
10 + 4 - 4 =
10.

hope that help you

ok you have to check if the air filter is clogged if that checks out ok, one of your injectors my not close properly and cause moore petrol to be consume.lock at this first and ask me more if you want. God luck Hans

Don't know the USA system but here in Europe the sister car with the same engine does 13 liters per 100 km on city, 9 l / 100 km on road and 12 l / 100 km on highway.

Manual 20-25 Auto 20-24. 20 around town 25 motorway so average 22-23 mpg.

it can be some reasons mybe cylinder head, inlet valve worn out.
it can be cuporator valve releasing more petrol into the inlet.
Brakes it can be. check contacpoint.