Table of contents: Officially-appointed garages 🠇 Accessory shops 🠇 Motor factors 🠇 Tyre and exhaust specialists 🠇 Other sources 🠇
| Length (distance) | ||
| Inches (in) | x 25.4= Millimetres(mm) | x 0.0394 = Inches (in) |
| Feet (ft) | x 0.305 = Metres (m) | x 3.281 = Feet (ft) |
| Miles | x 1.609 = Kilometres (km) | x 0.621 = Miles |
| Volume (capacity) | ||
| Cubic inches (cu in; in³) | x 16.387 = Cubic centimetres (cc; cm³) | x 0.061 = Cubic inches (cu in; in³) |
| Imperial pints (Imp pt) | x 0.568 = Litres (I) | x 1.76 - Imperial pints (Imp pt) |
| Imperial quarts (Imp qt) | x 1.137 = Litres (I) | x 0.88 = Imperial quarts (Imp qt) |
| Imperial quarts (Imp qt) | x 1.201 = US quarts (US qt) | x 0.833 = Imperial quarts (Imp qt) |
| US quarts (US qt) | x 0.946 = Litres (I) | x 1.057 = US quarts (US qt) |
| Imperial gallons (Imp gal) | x 4.546 = Litres (I) | x 0.22 = Imperial gallons (Imp gal) |
| Imperial gallons (Imp gal) | x 1.201 = US gallons (US gal) | x 0.833 = Imperial gallons (Imp gal) |
| US gallons (US gal) | x 3.785 = Litres (I) | x 0.264 = US gallons (US gal) |
| Mass (weight) | ||
| Ounces (oz) | x 28.35 = Grams (g) | x 0.035 = Ounces (oz) |
| Pounds (lb) | x 0.454 = Kilograms (kg) | x 2.205 = Pounds (lb) |
| Force | ||
| Ounces-force (ozf; oz) | x 0.278 = Newtons (N) | x 3.6 = Ounces-force (ozf; oz) |
| Pounds-force (lbf; lb) | x 4.448 = Newtons (N) | x 0.225 = Pounds-force (lbf; lb) |
| Newtons (N) | x 0.1 = Kilograms-force (kgf; kg) | x 9.81 = Newtons (N) |
| Pressure | ||
| Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 0.070 = Kilograms-force per square centimetre (kgf/cm²; kg/cm²) | x 14.223 = Pounds-force per square inch (psi; lbf/in²; lb/in²) |
| Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 0.068 = Atmospheres (atm) | x 14.696 = Pounds-force per square inch (psi; lbf/in²; lb/in²) |
| Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 0.069 = Bars | x 14.5 = Pounds-force per square Inch (psi; lbf/in²; lb/in²) |
| Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 6.895 = Kilopascals (kPa) | x 0.145 = Pounds-force per square inch (psi; lbf/in²; lb/in²) |
| Kilopascals (kPa) | x 0.01 = Kilograms-force per square centimetre (kgf/cm²; kg/cm²) | x 98.1 = Kilopascals (kPa) |
| Millibar (mbar) | x 100 = Pascals (Pa) | x 0.01 = Millibar (mbar) |
| Millibar (mbar) | x 0.0145 = Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 68.947 = Millibar (mbar) |
| Millibar (mbar) | x 0.75 = Millimetres of mercury (mmHg) | x 1.333 = Millibar (mbar) |
| Millibar (mbar) | x 0.401 = Inches of water (inH₂O) | x 2.491 = Millibar (mbar) |
| Millimetres of mercury (mmHg) | x 0.535 = Inches of water (inH₂O) | x 1.868 = Millimeters of mercury (mmHg) |
| Inches of water (inH₂O) | x 0.036 = Pounds-force per square inch (psi; lbf/in²; lb/in²) | x 27.68 = Inches of water (inH₂O) |
| Torque (moment of force) | ||
| Pounds-force inches (lbf in; lb in) | x 1.152 = Kilograms-force centimetre (kgf·cm; kg cm) | x 0.868 = Pounds-force inches (lbf in; lb in) |
| Pounds-force inches (lbf in; lb in) | x 0.113 = Newton metres (Nm) | x 8.85 = Pounds-force inches (lbf in; lb in) |
| Pounds-force inches (lbf in; lb in) | x 0.083 = Pounds-force feet (lbf·ft; lb ft) | x 12 = Pounds-force inches (lbf in; lb in) |
| Pounds-force feet (lbf·ft; lb ft) | x 0.138 = Kilograms-force metres(kgf·m; kg·m) | x 7.233 = Pounds-force feet (lbf·ft; lb ft) |
| Pounds-force feet (lbf·ft; lb ft) | x 1.356 = Newton metres (Nm) | x 0.738 = Pounds-force feet (lbf·ft; lb ft) |
| Newton metres (Nm) | x 0.102 = Kilograms-force metres (kgf·m; kg·m) | x 9.804 = Newton metres (Nm) |
| Power Horsepower (hp) | x 745.7 = Watts (W) | x 0.0013 = Horsepower (hp) |
| Velocity (speed) | ||
| Miles per hour (miles/hr; mph) | x 1.609 = Kilometres per hour (km/hr; kph) | x 0.621 = Miles per hour (miles/hr; mph) |
| Fuel consumption* | ||
| Miles per gallon, Imperial (mpg) | x 0.354 = Kilometres per litre (km/l) | x 2.825 = Miles per gallon, Imperial (mpg) |
| Miles per gallon, US (mpg) | x 0.425 = Kilometres per litre (km/l) | x 2.352 = Miles per gallon, US (mpg) |
| Temperature | ||
| Degrees Fahrenheit = (°C x 1.8) + 32 | Degrees Celsius (Degrees Centigrade;°C) = (°F - 32) x 0.56 | |
* It is common practice to convert from miles per gallon (mpg) to Htres/100 kilometres (1/100km), where mpg x 1/100 km = 282
Spare parts are available from many sources, including maker's appointed garages, accessory shops, and motor factors. To be sure of obtaining the correct parts, it will sometimes be necessary to quote the vehicle identification number. If possible, it can also be useful to take the old parts along for positive identification. Items such as starter motors and alternators may be available under a service exchange scheme -any parts returned should always be clean.
Our advice regarding spare part sources is as follows.
Officially-appointed garages
This is the best source of parts which are peculiar to your car, and which are not otherwise generally available (eg badges, interior trim, certain body panels, etc). It is also the only place at which you should buy parts if the vehicle is still under warranty.
Accessory shops
These are very good places to buy materials and components needed for the maintenance of your car (oil, air and fuel filters, spark plugs, light bulbs, drivebelts, oils and greases, brake pads, touch-up paint, etc). Components of this nature sold by a reputable shop are of the same standard as those used by the car manufacturer.
Besides components, these shops also sell tools and general accessories, usually have convenient opening hours, charge lower prices, and can often be found not far from home. Some accessory shops have parts counters where the components needed for almost any repair job can be purchased or ordered.
Motor factors
Good factors will stock all the more important components which wear out comparatively quickly, and can sometimes supply individual components needed for the overhaul of a larger assembly (eg brake seals and hydraulic parts, bearing shells, pistons, valves, alternator brushes). They may also handle work such as cylinder block reboring, crankshaft regrinding and balancing, etc.
Tyre and exhaust specialists
These outlets may be independent, or members of a local or national chain. They frequently offer competitive prices when compared with a main dealer or local garage, but it will pay to obtain several quotes before making a decision. When researching prices, also ask what "extras" may be added - for instance, fitting a new valve and balancing the wheel are both commonly charged on top of the price of a new tyre.
Other sources
Beware of parts or materials obtained from market stalls, car boot sales or similar outlets. Such items are not invariably sub-standard, but there is little chance of compensation if they do prove unsatisfactory. In the case of safety-critical components such as brake pads, there is the risk not only of financial loss but also of an accident causing injury or death.
Second-hand components or assemblies obtained from a car breaker can be a good buy in some circumstances, but this sort of purchase is best made by the experienced DIY mechanic.