A14. In most circumstances, no. The nature of Iridium spark plugs means that they are able to utilise a larger gap setting while actually requiring less voltage and straining the ignition system less. If you *have* to regap Iridium spark plugs then do so with extreme care. Do not use a slide type gapping tool or put pressure on the brittle centre electrode in any way as it may become damaged.

Most forum members agree that the stock Champions are just as good under most conditions as considerably more expensive plugs, including Bosch Platinums. Some have said that the "performance gains" claimed by some are due only to the use of new plugs, rather than special new plugs. The best oil is synthetic - it provides more protection during cold starts, when most engine wear occurs, and is more durable than standard oils. See similar questions...

First, you'll need anti-seize compound (just a little!), and a spark plug wrench or a socket with at least one extension - six inches is usually a good length - because modern cars often have the spark plugs at the bottom of a tube. Spark plug sockets have a rubber gasket in them which helps to grip the plug, helping it to come out more easily. See similar questions...

In terms of benefit, iridium plugs are similar to platinum plugs. They'll last longer than copper, but they won't give you any performance improvement. They'll withstand the higher heat of a high-compression racing engine, but so will a copper plug that's one or two heat ranges colder than stock. Iridium plugs last longer, but they won't make your car go any faster than copper. Splitfire plugs actually have some promise for increasing gas mileage in a granny driven car, but no performance gains. See similar questions...

Both the VE and VG use the NGK plug as a stock spark plug. The VE requires a platinum plug, which can run fairly expensive, at about $9/plug. I don't have the part numbers for this plug yet. The VG also uses an NGK plug, but they are non-platinum and cost just over $1/plug. Part numbers: Standard Type BKR6ES-11; Hot Type BKR5ES-11; Cold Type BKR7ES-11; Plug Gap 0.039 - 0.043 in (1.0 - 1.1 mm). Check your coolant level. this is a common problem. See similar questions...

Indmar has not tested and cannot approve the use of split fire spark plugs. Incorrect spark plugs can foul, cause radio frequency interference, cause the engine to run poorly, and may cause severe engine damage from detonation. Your warranty does not cover damage caused by the use of products not recommended by Indmar. The operator lists the recommended spark plug for your engine. See similar questions...

You may use either the aircraft or automotive spark plugs. There are several hundred airplanes running the EIS with automotive plugs. Additionally, you must verify that the heat range of an automotive plug is correct for your engine or you risk causing severe damage. We prefer, however, the aircraft plugs as they have been designed to work with aircraft engines and do not require any modifications for installation. See similar questions...

Improper installation may cause poor performance and could result in costly engine damage. Click here for a table listing torque recommendations for the DENSO Iridium Power spark plugs. See similar questions...

A5. That really depends on what you want from your plugs. Denso's Iridium Power offer the best performance but have a shorter service life than NGK's Iridium IX. Please consult our about Iridium spark plugs page for a more detailed comparison. See similar questions...

Mike Jukes uses the NGK 4 prong type which he thinks in theory are better than splitfires and they seem to work. Roy Tomlinson says try Bosch Super 4's as they've passed his doorstep challenge. They do work and make the car feel a bit crisper! See similar questions...

Plugs are also available from your local Vauxhall dealer, Part number 91143776. 4 plugs cost about ?9. The first two blocks of digits identify the body type, production year, the plant where it was manufactured and the chassis No. See similar questions...