Avid car collector Jay Leno wrote a hilarious piece on car user manuals, observing how much they, and their readers, have changed over the years.

Earlier guides assumed the user actually knew how cars worked and could easily service them themselves. Today’s guides assume (correctly) that the user knows next to nothing, except perhaps where to put the gas in.

Here are some of Leno’s funnier examples:

A. Old guide: Removing the Cylinder Head: Obtain a block of wood approximately the size of the combustion chamber and place this under the valve heads on the number one cylinder. Press down on the valve collars and extract the split collars. Remove collars, valve springs and spring seats. Repeat for the remaining five cylinders. Valves are numbered and must be replaced in original location. Number one cylinder being at the rear, that is, the flywheel end.

New guide: Changing the battery: Battery disconnection, removal or replacement should only be carried out by qualified personnel. Consult your dealer.

B. Old guide: In the event you need to remove the engine, gearbox and clutch, in the event it is necessary to carry out a repair of all the above units, notice that the gearbox may be removed from the engine when the floorboards have been removed and the rear of the engine has been supported. Removal of the gearbox will give access to the clutch.

New guide: If engine warning light goes on, consult your dealer. 

C. Old guide: To raise the headlamp beam, rotate spring-loaded screw on top of lamp clockwise. To lower beam, turn counter-clockwise. To adjust headlamp beam left or right, slacken the two hexagon-headed screws, one on each side of reflector rib assembly, and move the reflector assembly to the desired position. 

New guide: Do not attempt to adjust headlights. See your dealer.

• An explanation of the correct “ignition point settings”, showing how to “adjust the distributor and vacuum brake”. The guide states: Your Ford dealer can make this adjustment for you, but there’s no reason you can’t do it yourself. Right, and while your at it, you can be servicing your washer and drier.

• A guide for an old car made partly of wood states: If flames start licking over the front of the hood, shut off fuel and increase speed until flames blow out. Yikes – talk about a “hot rod”.
  

• This one is simple and to the point: After 1,000 miles, disassemble engine, check everything, reassemble. Got it!

• the product being document
• the user reading the document

They just don’t make users like they used too…