41 guides on motoring
What a car costs to run, and the ratios under it. Fuel and charging, tyres and gearing, insurance and what depreciation quietly takes each year — with the annual mileage every one of those figures depends on stated up front.
Ranked by how many pages of this site link to them, not by traffic.
The break-even is a division, and the number underneath it moves more with where you charge than with which country you live in. Electricity and fuel prices from 2025 and 2026, the arithmetic in full, and the point at which an electric car stops saving anything at all.
Marco Bianchi · 15 min read
Three ways to put the same car on the drive, priced over five years at the same interest rate. The monthly payments rank the options in exactly the reverse order of what they cost — and the gap turns out to be a single, computable number.
Marco Bianchi · 15 min read
One country gives you a formula that changes with the car's horsepower and the distance driven, one gives everybody the same figure per kilometre, and one publishes a table per model. All three are meant to cover the whole cost of running a car, and all three leave out things people assume are included.
Camille Laurent · 12 min read
Nobody negotiates a company car as a pay cut, but that is what the tax treatment makes it. Three countries value the same car by three completely different methods, one of them changed in 2025 in a way that nearly doubled the figure, and in all three an electric car is taxed at a fraction of the same vehicle with an engine.
Camille Laurent · 13 min read
There is no single towing capacity. There are four or five separate limits, and the one that binds is rarely the tow rating on the brochure — it is usually the vehicle's own weight budget, quietly consumed by the people sitting in it.
Marco Bianchi · 16 min read
Engine rpm reaches the road through one unbroken multiplication chain, and the last link is the tyre. Change the tyre's rolling circumference and the speedometer goes wrong by exactly that percentage — in a direction the law cares about.
Marco Bianchi · 15 min read
Total stopping distance is two distances added together, and they follow different laws — one grows with speed, the other with speed squared. That single fact explains why doubling your speed roughly triples the distance.
Marco Bianchi · 17 min read
Smoother driving, correct tire pressure, less weight and lower motorway speed can cut fuel use noticeably. Here is what each one is worth.
Marco Bianchi · 5 min read
Linear dimensions, volumetric weight and typical cabin and checked limits explained, so your bag clears the gate without a surprise fee.
Marco Bianchi · 5 min read
One knot equals exactly 1.852 km/h and about 1.15 mph. See the exact conversion factor, why the nautical mile exists, and where aviation and shipping use knots.
Marco Bianchi · 4 min read
Jet lag eases at roughly one day per time zone crossed. Learn why eastward travel is harder, and follow a light, sleep and meal plan to reset your body clock faster.
Marco Bianchi · 4 min read
Estimate a flight's duration by dividing the great-circle distance by cruise speed, then adding taxi, climb and descent overhead. A simple, reliable method.
Marco Bianchi · 4 min read
Torque is the twisting force an engine makes; horsepower is how fast it does work. Learn the hp = torque × rpm ÷ 5252 link and why both numbers matter.
Marco Bianchi · 4 min read
Mileage reimbursement pays a set rate per mile driven for work. Learn how the rate is set, how the IRS, HMRC and URSSAF differ, and how to keep a compliant log.
Marco Bianchi · 4 min read
How much does it actually cost to fuel an EV versus a gas car each year? We compare cost per mile from electricity and gasoline, plus the factors that swing the answer.
Marco Bianchi · 4 min read
Fuel is only part of what a mile costs. Add depreciation, insurance and maintenance to find your true cost per mile — and why it is higher than the pump suggests.
Marco Bianchi · 5 min read
Leasing means lower monthly payments and endless flexibility; buying costs more up front but leaves you owning an asset. Here is how the total cost really compares.
Marco Bianchi · 4 min read
Use the vehicle placard pressure, not the number on the tire. Learn why the sidewall figure is a maximum, why pressure is set cold, and how temperature moves it.
Marco Bianchi · 4 min read
The numbers on your tire sidewall decode into width, aspect ratio and rim diameter. Learn to read 205/55 R16 and work out the real overall diameter.
Marco Bianchi · 4 min read
The loan is written like a car loan and behaves like a mortgage on an asset that loses value like a car. That combination opens a negative-equity window measured in years — and the number that decides the purchase is the cost per night of use.
Marco Bianchi · 14 min read
Efficiency rises with compression ratio, so why do petrol engines stop around 12:1? Because compressing a charge heats it — r to the power of gamma minus one — and above a certain temperature the unburnt end gas lights itself.
Marco Bianchi · 18 min read
The speedometer is the famous consequence, and the least expensive one. The same number sets your odometer and therefore your lease bill, your effective final drive and cruising rpm, and what the ABS believes about wheel slip.
Marco Bianchi · 13 min read
Going from 10 to 20 mpg saves six times more fuel than going from 30 to 40, over the same distance. The reason is that fuel used is the reciprocal of fuel economy — and it changes which vehicle you should replace first.
Marco Bianchi · 11 min read
Several European countries tax cars on an administrative power figure that nobody has ever measured — it is the output of a formula, the formula differs by country, and it has been rewritten more than once. Here is what each market actually taxes, worked through on one car.
Marco Bianchi · 15 min read
A dipped beam is aimed downward by a fraction of a degree, so its reach on flat road is a single division. Do it and you find that at motorway speed the beam is shorter than the stopping distance — and that a loaded boot can throw the whole calculation away.
Marco Bianchi · 12 min read
Towing limits tell you whether you may hitch up. Tongue weight tells you whether the combination will stay straight. It is set by where the trailer's centre of gravity sits relative to its axle, it moves faster than anyone expects, and the recommended bands are not the same on the two sides of the Atlantic.
Marco Bianchi · 13 min read
Two axle weights and a wheelbase give you the exact position of a car's centre of gravity. From there the arithmetic keeps going: how much weight braking moves forward, why the rear axle is the one that runs out of grip, and why a load behind the rear axle takes weight off the front.
Marco Bianchi · 13 min read
Estimate remaining range from fuel left and your car's economy. A simple method for gas and diesel, with a worked example and a safety margin.
Marco Bianchi · 3 min read
How much CO₂ does a flight emit? Learn the per-passenger-kilometre figures, why short hops are worst per mile, and what the numbers really mean.
Marco Bianchi · 2 min read
Charging time is battery energy needed divided by charger power. See how home AC and public DC compare, and why fast charging slows past 80%.
Marco Bianchi · 3 min read
Estimate a drive's real duration: divide distance by average speed, then add stops for fuel, food and rest. A simple method with a worked example.
Marco Bianchi · 2 min read
Battery size, efficiency, speed, cold weather and terrain all move an EV's real range far from the sticker figure. Here's how each factor works.
Marco Bianchi · 2 min read
Both numbers are pure geometry — one is the volume a piston sweeps, the other a ratio of two volumes — and both are read as if they described power. Here is each derivation worked on real engines, and exactly what each number can and cannot support.
Marco Bianchi · 14 min read
The legal minimum exists to define an offence, not to describe a safe tyre. Tread does one job — getting water out of the contact patch — so its effect is near zero in the dry and decisive in the wet. Here is what the numbers say, and how to measure your own.
Marco Bianchi · 13 min read
Comparing a drive with a train ticket on fuel alone understates the car by a factor of five. Here is how to build the marginal cost of a trip, how to separate it from the fixed cost of ownership, and why both numbers are correct answers to different questions.
Marco Bianchi · 12 min read
A car's CO2 number and its fuel consumption number are the same measurement in different units, tied together by chemistry that you can do on paper. Here is the derivation, and then the three things the figure quietly leaves out.
Marco Bianchi · 11 min read
Leasing means lower payments but no ownership; buying costs more per month but the car is yours. Here's how each works and which fits your situation.
Marco Bianchi · 3 min read
Divide distance by fuel economy, then multiply by the price. Here's the calculation, metric vs mpg, what pushes it up, and how to split the cost.
Marco Bianchi · 3 min read
Charging cost is energy added times your electricity price. Here's the sum, home vs public charging, cost per 100 miles, and how it compares to gas.
Camille Laurent · 3 min read
MPG is how far a car goes on a gallon — higher is better. Here's what it means, how it relates to L/100 km, why your real figure is lower, and how to improve it.
Marco Bianchi · 3 min read
One triangle, three formulas. Learn speed = distance / time, rearrange it for distance or time, and keep your units consistent so the answer is right.
Marco Bianchi · 4 min read