CHRISTMAS OFFER Subscribe to Cotswold Life today CLICK HERE

Can you trust your car’s speedometer?

10:08 13 March 2016

Trust your cars speedometer and it will keep you within the law

Trust your cars speedometer and it will keep you within the law

PA

Is your car’s speedometer telling the truth? None of us wants to end up with a speeding ticket when we think we’ve been travelling at the legal permissible speed, so it’s important that the speed you see is accurate.

The simple answer is yes, you can trust your car’s speed reading. While some much older cars that are now very much classics might have speedos that tell fibs, any car built from the 1980s onwards will have a speedo that is reasonably accurate. Even allowing for wear, tear and age, a speedo is not going to start telling you are driving at the legal limit when, in fact, you are going faster.

Don’t panic

Cars made in modern times are built with speedometers that deliberately over-read by a small amount. This is usually not obvious at lower speeds in town or even on 40mph stretches of road. Head on to faster roads, such as a 60mph limit or the motorway and you may notice some discrepancy between the reading on your car’s speedo and that on a satellite navigation system or an app on you smartphone.

Don’t panic about this. For one thing, if the speed on the sat-nav or phone is lower than the one on the car’s dash, you are safely within legal limits. Sat-navs and phones use GPS tracking to calculate speed based on time and distance – great for military aircraft and ships but not so good for cars on normal roads as it doesn’t account for undulations and curves in the road.

The main reason car speedos over-read is because car companies do not want to face legal action for a driver going too quickly. This could be legal action from a driver who feels a false reading caused them to be prosecuted for speeding or it could be a criminal prosecution if someone was hurt as a result of excessive speed.

Margins

So, all cars’ speedo’s over-read, but this has to be within a 10% 
margin as it could be just as dangerous for a car to be travelling too slowly on a road and cause 
hold-ups and frustration for other drivers. The speedo must never under-read, so if it says 60mph 
it cannot be any more than that speed.

A worry for some drivers is the speedo might become incorrect as the tyres wear down. However, as the tyres wear, the speedo is only likely to over-read very slightly more, not less, so it won’t risk you speeding when you think you are within the law.

What can catch you out is if you change to a set of larger wheels and tyres. If the rolling circumference of the new tyres is larger than the original ones, the speedo can begin to under-read and put you at risk of speeding without knowing it. Check with your tyre supplier because you may have to get your car’s speedo recalibrated to allow for this. Otherwise, trust your car’s speedometer and it will keep you within the law.

0 comments

Welcome , please leave your message below.

Optional - JPG files only
Optional - MP3 files only
Optional - 3GP, AVI, MOV, MPG or WMV files
Comments

Please log in to leave a comment and share your views with other Cotswold Life visitors.

We enable people to post comments with the aim of encouraging open debate.

Only people who register and sign up to our terms and conditions can post comments. These terms and conditions explain our house rules and legal guidelines.

Comments are not edited by Cotswold Life staff prior to publication but may be automatically filtered.

If you have a complaint about a comment please contact us by clicking on the Report This Comment button next to the comment.

Not a member yet?

Register to create your own unique Cotswold Life account for free.

Signing up is free, quick and easy and offers you the chance to add comments, personalise the site with local information picked just for you, and more.

Sign up now

More from Cotswold Life

Yesterday, 10:40

Twinkling Christmas lights, frosty landscapes and breathtaking views, it doesn’t get much prettier than these picture-perfect Cotswold scenes

Read more
Yesterday, 14:24

The weekend is fast approaching and for those still deciding how to spend their Friday through to Sunday, we pick 5 of the best ways to spend your weekend in the Cotswolds

Read more
Yesterday, 11:58

Patsy Holdsworth believes she has found the perfect place to spend the festive season with friends and family

Read more
Yesterday, 11:29

BBC Radio Gloucestershire’s Mark Cummings gives us his recommendations on how to enjoy Christmas in the Cotswolds

Read more
Yesterday, 11:27

Cotswold Life’s Good Food Guy introduces the local producers who really make your Christmas...

Read more
Yesterday, 10:46

Getting outdoors is great for physical and mental wellbeing, staving off the winter blues, and balancing the naughty-but-nice indulgences of Christmas. Sian Ellis picks 12 days of festive fun to enjoy in the beautiful Cotswold countryside

Read more
Friday, December 2, 2016

As the nights close in and the air begins to bite, people turn to their homes for comfort and warmth. Yet a home’s heating, thick curtains and draught excluders might count for nothing if the carpet is thin and worn, or if any hard floors are lacking in thick super soft or wool pile rugs.

Read more
Friday, December 2, 2016

Home to some of the country’s most breathtaking architecture and picturesque gardens, the Cotswolds boasts plenty of beautiful stately homes you need to visit. We pick 8 special locations that are made even more magical as Christmas approaches

Read more
Friday, December 2, 2016

From mini Norway spruces to luxury Nordman firs, here are six of the best places to get a luscious, green tree in the Cotswolds this festive season.

Read more
Thursday, December 1, 2016

The Cotswolds are abundant with picture perfect locations ideal for a ramble. Gather loved ones, wrap up warm and blow away the cobwebs with one of these winter walks in the region

Read more
Wednesday, November 30, 2016

Indulge in a truly enjoyable evening with a delicious 7 course tasting menu prepared by our Head Chefs Sue & Mark Stinchcombe.

Read more
Wednesday, November 30, 2016

Heritage specialist Bruce Clark from built environment consultancy Nash Partnership tells us what to look for before buying or renovating an old property

Read more
Tuesday, November 29, 2016

Stay at Whatley Manor before Christmas and receive a £50 credit to use however you choose to, in the hotel, restaurants or in Aquarias Spa. You will also receive a festive gift on departure.

Read more
Tuesday, November 29, 2016

Win a three or four night short break in your choice of 3 luxury holiday apartments set within the award winning garden at RHS Rosemoor in North Devon

Read more

Newsletter Sign Up

Sign up to the following newsletters:


Family Business Awards link

Topics of Interest

Food and Drink Directory
A+ Education

Subscribe or buy a mag today


subscription ad
Cotswold Life Application Link

Local Business Directory

Cotswold's trusted business finder


Follow us on Twitter


Like us on Facebook

Job search in your local area



Search For a Car In Your Area

Property Search