Is it eco-friendly, and hence more fuel efficient, to use cruise control on a motorway?
In the right circumstances, cruise control is an important boost to fuel economy. It is particularly benificial on motorways to maintain a constant speed which can be difficult due to your foot allowing the speed to vary slightly.
One or two exceptions you should be aware of. On steep uphill gradients cruise control tends to cause wider throttle openings to maintain speed, and it may cause an unnecessarily downward gear change; conversely, on downward slopes, it may brake to slow the car to maintain the selected speed thus losing momentum. By not using cruise control in the aforementioned circumstances, you can maintain a steady pressure on the throttle (rather than pushing it to the floor) giving a slight decrease in speed uphill which can then be offset by picking up speed (on the same accelerator pedal opening) on the downhill gradiant.
Overall, certainly on the UK motorway network, and discounting other factors, such as heavy traffic, then cruise control is probably a saver of fuel to the order of five percent or so.
No Claim Bonus
I have used a company car for the best part of 20 years, but am about to change jobs and will be using my own car in the future. I have a clean licence and have never claimed on the company insurance all the time I was using their car, but I cannot find an insurer who will accept my years of blemish-free motoring and give an appropriate no-claims discount. What do you suggest?
Contrary to what you understand, most insurers welcome former company car drivers who have proof of a clean driving and claim-free history. As you prefer searching on-line, the problem (as we see it) is finding the part of the insurers website to be able to show your status as a claim-free former company car driver.
We suggest you complete the online details as if you had the maximum no-claims discount (which you have), note the reference number and then phone the insurer to clarify things. You will need to provide proof of your no-claims status from your old employer's insurer. If the worse case scenario, you should be able to obtain an introductory discount, but hold out for a full discount.
My grandson, who is five years old, often sits in the front seat of his parents car in a child booster seat. Should the airbag be de-activated in these circumstances?
Difficult one and one where we feel the law may be a little vague, but regulations indicate that the airbag should be turned off if the child carrier is a rear-facing device; my own personal opinion is that common sense must prevail and that all young children and babies should be correctly seated in the rear - but how often is common sense applied nowadays!
That said, if you cannot persuade your family to seat their off-spring in the back, then check carefully the manufacturer's handbook for their advice on the particular car, ie., pushing the front seat right back if the airbag is still turned on may be advised.
Another problem is that while some vehicles' airbags can be deactivated simply by operating a switch, others require a visit to the dealer to get the bag switched off; the disadvantage with the latter is that adult passangers would be left vunerable with no airbag protection in the case of an accident.
Is damage likely to occur to my car as my wife insists on turning the steering wheel (when stationary) to engage the column lock? The reason I ask is that years ago I was told not to turn the steering when stationary as this could strain the steering linkage and cause undue tyre wear.
It is not necessary to engage the column lock as the internal lever would soon snap into place if anyone tried to turn the steering wheel with no key in the ignition, such as if a thief was trying to drive away your car after attempting to 'hot wiring' it.
By engaging the steering lock each time the vehicle is parked, it makes it difficult to release the mechanism later when the ignition key is engaged without jiggling the steering wheel to-and-fro against resistance. This action (as you are aware of) causes undue strain to the key, lock mechanism and the steering system; it is a habit that is best avoided.
Could you explain why insuring a vehicle with a replacement value of, say, £1500 at most, costs me almost as much as obtaining cover for a brand new car which has a much higher value?
This is due mostly to third-party liability, ie., the damage you are capable of doing with your car (whether new or old) to another vehicle, or in fact anything that could be damaged if you hit it. Another factor of increasing importance nowadays is the claim for compensation that can result after a personal injury and, of course, the high cost of litigation that usually accompanies a claim. See also our reply to J.A. later in this postbag.
The ABS warning light on my Ford Scorpio operates as normal when the ignition is turned on, but occasionally it comes on again as I'm driving along. Sometimes it just flickers on and off, but on one occasion it stayed on so I stopped the car and switched. On restarting everything operated as it should and all warning lights were normal. Any help would be appreciated.
You should take the car to your Ford dealer straight away as they have the correct test rig and equipment to find out what is causing this intermittent fault. The ABS warning lamp should initially light up when the ignition is switched on while the on-board computer carries out a self-check of the system.
When driving along the computer continually monitors the operation of the ABS and if a defect is identified the system is shut down. In these circumstances the braking reverts to basic non-ABS manual operation.
In your case the fault appears to be intermittent which makes it all the more difficult to trace. It could be the computer, but the garage should first of all test the connections, as well as the warning light circuit, to ensure all joints are clean and secure.
The fascia, steering wheel and column on my Ford Escort vibrate at speeds above approximately 60mph, but tend to lessen again if I increase the speed by about 5 miles per hour. The front tyres have been balanced and the tyre fitter checked the suspension at the same time. Any suggestions what to try next?
It appears you have dealt with the usual causes of this annoying fault. Assuming the tyre fitter knew what he was doing, we feel the problem could be due to a worn steering ball joint, or maybe the drive shafts and wheel bearings are past their best.
Look under the car at the drive shaft gaiters to see if they are sound and that no lubricant has been centrifugally thrown out around the underbody. Although this is a bit of a long shot, it may be due to vertical balance of the wheel and tyre as opposed to side-to-side balancing.
I have always fitted a racing mascot
to the bonnet of my car, usually about half way between
the front edge of the panel and the wind-screen. I understand
that provided it's not positioned right at the front of
the bonnet this is legal, am I correct? A garage told me
it's probably illegal.
Basically the regulations say that
no mascot, emblem or ornament, may be fitted on a vehicle
registered after 30th September 1937 that is placed in a
position likely to injure a person in a collision.
Bearing in mind that the design of a modern
car (unlike the design of cars in the Thirties) is such
that the bonnet and windscreen should provide a cushion
if a pedestrian is struck, then fitting an ornament is probably
dangerous and illegal. The likely exceptions are the spring
loaded type mascots as used by Mercedes, for instance.
My daughter has recently passed her
driving test on a car with automatic transmission and I
realize she cannot drive a vehicle with a manual gearbox.
However, does the regulations permit her to drive a car
fitted with the new fangled switchtronic or multitronic
systems? This is causing us some confusion as my car dealer
gave us a non-committal answer.
understanding of the regulations is that your daughter can
legally drive a car with this kind of transmission where
gear changes are made by moving buttons/paddles on the steering
wheel, or even by moving a gearstick.
It appears that as long as no clutch pedal
operation is involved in changing gear the system will be
classified as automatic.
Whenever I change my car I always buy from new and generally change it every five years, or at about the 50,000 mile point. Can you tell me at what stage in the car's life does performance and economy begin to fall away as I feel this would be the ideal time to trade in?
long is a piece of string? It is impossible to give a definitive answer as it depends on how the car is driven, its servicing record, conditions it's used under, etc. It is a fact that a new vehicle takes a while to "loosen up", or what we used to term "run in", before all the running surfaces have "bedded" together; this can take a thousand miles or so. That said, in this day and age with such fine engineering tolerances, any change is hardly noticeable and depends on how the car is driven and other circumstances.
At what stage performance tends to drop off we would say its reasonable to assume that an average size car, used under normal motoring conditions, would probably start to experience some slight deterioration in performance (and hence economy) due to wear and tear at about 75,000 miles. However, no hard and fast rule can be applied as it dependants so much on how the car is driven, fuel used, conditions of use, frequency of servicing, etc.
Could you explain why is it that
an automatic gearbox always seems to have fewer gears than
a manual. Surely to obtain similar performance and economy
they need the same number of ratios?
automatic gearbox has a torque converter instead of a clutch,
the latter being generally used in conjunction with a conventional
manual change gearbox.
The torque converter operates on an entirely
different principle to a clutch, but still achieves the
same end result by allowing the power motion between the
engine and gearbox to be split and the drive taken up gradually.
However, instead of a dry friction plate to transmit this
drive, in most auto gearboxes it is transmitted by the centrifugal
action of gear oil (ATF) in the torque converter which permits
a high degree of slip without overheating the unit (the
same amount of slip in a standard clutch would rapidly wear
and burn out the dry friction linings).
This deliberate built-in slipping action of
a torque converter means a greater ratio can be accessed
in each gear, giving a near-perfect range of ratios between
engine and transmission until the unit stabilises the drive
one to one. In effect, this variable ratio gives an automatic
gearbox a greater range of gears between the lowest and
highest ratio than a manual transmission.
In fact, the modern trend is for manufacturers
to offer four-speed or five-speed automatic gearboxes, especially
in the more up-market models of a range.
I recently saw mentioned in a motoring magazine the term
'brake-by-wire'. Could you explain what this is all about?
You probably read something about
the technology as used in the Mercedes Benz SL which saw
the introduction of the world's first brake-by-wire system.
This is an electro-hydraulic configuration developed by
Bosch and applied as Sensotronic Brake Control (SBC) by
The principle of brake-by-wire is the
replacement of the traditional vacuum and hydraulic system
with electronic control to give greater response and precision
of braking. When the brakes are applied, sensors measure
the speed and force of the driver's action on the pedal
and relay this information to the SBC control unit, along
with data collected by other sensors on the car.
This information is immediately processed
by the control unit which in turn generates separate signals
to apply the correct braking force to each brake disc and
hence the wheel. An example of its effectiveness is that
when braking on a bend, the SBC will brake the wheels at
the outer side of the curve harder than those on the inner,
thus increasing stability and reducing braking distance
compared to a car with a more conventional braking system.
On a wet road, the SBC can undertake imperceptible
brake impulses at regular intervals to remove water film
from the discs, ensuring the system always operates with
Cars of only a few years ago seemed to rattle and squeak,
even when comparatively young.
Having just bought a brand new car I am impressed
by its ride and it's so quiet without any noise from the
dashboard or other parts, whereas my old one used to have
lots of peculiar sounds, especially from the dash area.
What has been done to make modern cars so quiet?
would take most of the space available in this magazine
to fully explain the strides that have taken place in car
technology over the past ten years or so.
Suffice to say, and with particular reference
to instrument clusters, the latest electronic wizardry has
no mechanical connections, i.e., speedo cable or choke control,
between the dashboard and the engine or gearbox, thus the
transference of vibration and noise into the passenger compartment
Instruments/gauges nowadays generally function
in conjunction with sensors and an electronic management
system, so usually make no detectable sounds, and such things
as a choke control are becoming a distant memory to many
My car is in very good condition
for its age and is insured for its market value. But what
I do not understand is if its value gets less each year,
why does my premium still go up?
It is difficult to give a precise
answer to this query due to a number of different factors.
It is reasonable to assume that probably
around 20% of vehicle insurance premiums is used to pay
the cost of claims for write-offs, while most of the remainder
is taken to reimburse motorists for minor damage or to pay
third-party damage, as well as processing and running costs.
The percentage remaining is the profit element that any
organisation requires to survive and to invest in new products,
As cars get older their value may decrease.
But, if they are not written-off after a claim, the cost
of repairing them can be nearly as much as a new vehicle.
Additionally, supply and demand often dictates that spare
parts are more costly and difficult to obtain for older
Another factor that may be overlooked is that
it's as easy to knock someone over in an old car as it is
in a new one and third-party claims are probably one of
the biggest growth areas in these times of 'no win, no fee',
Last year while driving down to the
South of France we saw quite a few cars with British registration
that were not displaying a GB sticker. Is it still compulsory
to display this sticker nowadays?
understanding is that it is still necessary to have the
appropriate national sticker or badge on a car when traveling
in any European country, apart from the one in which the
car is registered.
Some modern number plates have the European
Union circle of stars (with an accompanying GB) on the left-hand
side of the licence plate. In this case you should not require
a separate sticker if driving within EU countries only.
However, do bear in mind that not all
European countries are in the EU. In non-EU countries we
advise a GB sticker.
My son's car has left unsightly oil
stains from an engine leak on our concrete driveway. What
is the best way to remove these blemishes as rubbing petrol
into them seems to have made things worse?
I understand your feelings having
suffered the same problem myself. In our case we removed
most of the oil from the driveway by rubbing in plenty of
washing-up liquid with a stiff brush (hands and knees job),
then washing away the resulting mess with a water hose.
This was repeated several times over the course of a week
and the stain gradually faded, assisted by the weather.
It might be worth trying a propriety
concrete cleaner if the above doesn't shift the stain.
The term 'brake fade' is often used in car test reports
I have seen in the past, but I have never understood exactly
what this is and under what conditions it can occur.
I have only ever experienced this
once (descending the steep hill into Lynmouth in north Devon
with a heavily laden car) and it wasn't a particularly pleasant
brakes are used hard and continuously on a steep descent
they can get very hot and overheat. If the braking surfaces
(pad or shoe friction material) warm beyond a certain
temperature they lose efficiency and hence grip, making
them less effective.
phenomenon is unlikely to happen nowadays with the improved
friction materials generally in use and, in any case, disc
brakes are not as prone to 'brake fade' as their earlier
drum counterparts. That said, if you ever notice the slightest
loss of braking effect on a long descent, stop immediately
and let things cool down before investigating further. If
in doubt stay where you are and seek professional advice.
I have often noticed mirages that appear to be small puddles
of water on the road. Naturally they disappear as you approach
them. What exactly causes these images, and what am I actually
all to do with light reflection as you surmise in your letter.
When light rays pass from one medium to another of a different
density, such as surrounding air to water, they are distorted
(this can be seen at its best when a straight stick is immersed
in water and appears bent).
In the case of mirages on the road, although
the surface of the carriageway may be perfectly dry, the
warmer air just above the tarmac is less dense than the
higher layers of air above it, so the rays of light which
would normally be reflected into your eyes as you peer at
the road ahead are bent and as they follow the road surface
it makes it appear wet.
All you actually see is a collection of light rays that
image of a patch of water - same principle is apparent in
sand of a desert.
Reading a recent road test report
in a car magazine, I was surprised to learn about the effect
that air-conditioning has on the car's overall fuel economy.
The report didn't say how much extra was actually used,
but is increased fuel usage a standard problem with air-conditioning
and by what amount does it reduce the number of miles per
gallon from a car when it is switched on?
is not possible for us to give a definitive answer to your
query, but we can say that generally driving any vehicle
with the air-conditioning switched on will reduce its fuel
economy, although this has a more marked effect on smaller
engined cars where the power absorbed to operate the aircon
is a larger proportion of the overall torque available to
move the car.
Other factors that affect the amount
of power the air-conditioning system absorbs from the engine
are the outside air temperature (the warmer the day, the
harder the unit must work to lower the temperature of air
being drawn in and hence the more energy from
the engine used), and the temperature level desired for
the interior. Again, the lower the inside temperature is
set, the more power that
is required from the engine and hence the additional fuel
On average, we estimate an increase of
approximately 10 to 25 per cent extra fuel is used to operate
the aircon in a medium sized family saloon being driven
sensibly on a fine summer day. Obviously, this usage will
lessen during the colder months when the system is used
mainly for dehumidifying and demisting purposes.
One thing always to bear in mind is that
it's important to operate an air-conditioning system on
a regular basis, even in the winter months. This will ensure
that the lubricating oil (which circulates with the refrigerant)
is distributed around the aircon components to prevent the
seals drying out.