What it means for classic car owners
Several stories have been carried by the motoring press in the last week stating a new government intention to impose a 0% tolerance on speeding motorists. Starting in Autumn, this will apply across Scotland and could be rolled out nationwide. Motorists breaking the speed limit by just 1 mph will be given a formal warning letter, and receive a fixed penalty of £100 if caught a second time. This clearly has implications for all motorists who must be doubly vigilant about their own speed, but where does this leave the classic motorist?
Regardless of whether you choose (or can afford!!) to do so, all P6 models irrespective of engine capacity are comfortably capable of breaking the UK’s 70 mph national speed limit. So how can you be sure you are always under the limit?
The Official Guidelines on Speed Enforcement
Presently, the Government and ACPO (Association of Chief Police Officers) speed enforcement guidelines recommends issuing speeding tickets for any car travelling at more than 10% + 2 mph over the zone’s limit. This was devised both to account for potential inaccuracy of speed cameras and speedometers, and to give the motorist the feeling that the system was fair by offering a generous tolerance. According to these guidelines, the maximum speed on a British motorway before you are sure to be issued with a fine is 79 mph, although anything over the limit is technically a motoring offence and these are only guidelines for the speed enforcement officers to follow. You may be stopped for doing anything over 70 mph, whereupon a speed enforcement officer could do any of the following:
Issue you with a verbal warning
Offer you the chance to attend a speed awareness course at your cost
Issue an FPN (fixed penalty notice) with a fine of £60 and 3 penalty points
Prosecute you for speeding. A fine of up to £1000 (or £2500 if speeding on the motorway), between 3 and 6 penalty points, and a possible driving disqualification.
For prosecution, the limit is 96 mph or greater in a 70 mph zone. According to the ACPO’s guidelines, officers are not recommended to prosecute below this speed.
The Legal Requirements for Your Car
Most cars (with the exception of three-wheelers and other curiosities) fall under MOT Class 4. In this class speedometers are not subject to testing, either for accuracy or even functionality. The only time your tester will look at your speedometer is to record the mileage reading on the odometer. If your speedometer is broken or wildly misreading your MOT man may mention it to your verbally, but it cannot be recorded as an advisory because it is not an official test item.
This leaves classic owners in a difficult position with regards to road speed compliance. You are legally required to drive within a specified speed limit (and if the stories are to be believed this may in time have a 0% tolerance) and yet there is no legal requirement to have an accurate or functioning speedometer fitted to your car, and no facility for you to have this independently verified by such an authority (eg VOSA) that would solidly stand in your favour in an appeal.
How does this affect P6s?
To begin on a positive note, most people now struggle to find tyres with the 80% aspect ratio (tyre wall height) of the original Pirelli Cinturatos and Dunlop SP Radials that were fitted to the cars when new. Many people now fit tyres with a 70% aspect ratio (185/70/14 being the most commonly available for V8s) which gives a marginally smaller wheel rolling radius. As such, you can take a crumb of comfort in the fact that your speedo will likely over-read by a few percent. An indicated 70 mph may be as little as 67 - 68 mph, but this is still no guarantee.
Many P6 speedometers also read erratically. They are least 40 years old and now suffering from inadequate lubrication. The only sure way to get a consistent and steady speedometer reading is to thoroughly lubricate or replace the angle drives and speedometer cable. This is especially key for cars with the round dials ‘S-spec’ instrument packs (as fitted to all Series 2 TCs and V8s, and NADA 3500S models) which have an unfavourably long speedo cable which goes through a series of undesirable curves in situ.
But neither of the above will guarantee an accurate speedometer. You can send the figures of your final drive ratio and tyre size off to a company like Speedy Cables who can recalibrate your speedometer to read accurately for your setup, but we recommend using a satnav to see how far out your existing speedo is reading. Check it throughout the speed range - just because it appears to read correctly at 30 mph doesn’t necessarily mean it will at 70 mph.
If in doubt, use a sat nav at all times - especially when travelling on motorways. Also bear in mind that sat navs give you your actual speed whereas speedometers (especially on modern cars) often deliberately overread by around 3 mph.
We strongly recommend you read the guidelines from the Association of Chief Police Officers on speed enforcement. We can find no reliable information on how to appeal against a speeding fine if your speedometer is inaccurate or misreading, but you can find information on appeals with this guide from Which.
Words: Michael Allen
Pictures: William Roberts
With thanks to Phil Allen for researching