How to drive down the cost of driving your car

[guest1521]

My son the other day asked: "Besides driving less or changing my car how can I cut my costs while I'm actually driving?"  Below is what I thought I'd tell the young man.

Then I thought I'd post it on the Forum to see if I've got it right - more or less. People here might think it useful, too. (Or they might not!)

Having begun, it ended up much longer than I'd guess. And it's probably not complete - p'raps not by some way!

WELL, HERE GOES:

Drive with empathy and sympathy for your car mechanicals - always. It becomes habit and then is easy.

Smooth 'average' progress never has to be slow 'average' progress.

'Fast' driving almost always does not equal 'hard' driving. F1 3x World Champ Alain Prost was renowned for smooth but fast driving. Deceptively fast, they say, because he was so smooth/undramatic. Besides, smooth driving equates to most grip. (??Would YOU know of today's reputed to be 'ultra-smooth but fast' motor-racing driver example a young guy now'd relate to??)

Jerky driving - forward or back, from side to side (that passengers feel) accelerates wear on many aspects of the car as well as tyres. (And less/lost grip.)

Cold starts cause much engine wear. Short starts, such as move out of garage and switch-off, are very bad. Oil not 'up', cylinder walls suffer petrol wash - among other things. Short, cold/cool runs are not at all good. But it's mostly counter-productive to run more miles unnecessarily.

Idling to warm from cold is counter-productive (not to mention inconvenient and fuel-wasting.) Warm-up takes longer while 'no-load state' means engineering tolerances remain 'micro-sloppy' for longer. In very cold weather/winter, however, idle for a time may be necessary to clear fogged windows inside and out. Clear (all-round) vision is more important than any other motoring consideration.

Much better in general for cold starts... low revs, soft/easy gearchanges and gentlest acceleration. Be 'easy' on the car for first 10 minutes from cold.

Snappy second-gear down-changes are hard on any gearbox - even more so when cold. Most-used (typically) second gear suffers most 'hammer' in any gearbox in any car, anyway. No need to shorten its life still  further.

Don't use clutch as a foot-rest ('riding' the clutch). It puts pressure on the thrust bearing - heats up, wears quicker.

Avoid 'slipping' the clutch (as far as possible). Badly wears the friction lining.

Avoid sitting stationary in gear for more than 30 seconds. Causes clutch parts to heat up and wear.

Don't use gear-lever as a hand-rest. Constant hand pressure wears critical components inside the gearbox.

Accelerate gently, adding more revs in progressively higher gears till top. Low/first is just a 'get rolling' or steepest of hills gear. Because hard acceleration in lower gears transmits more 'twisting force' (hard-wearing torque) through all mechanicals.

Minimise braking through maximum observation and anticipation. Saves brakes, fuel, mechanical stress.

Lowest possible revs while making desired rate of progress.... but never lug the engine which creates more cylinder wear, more bearing wear and head-gasket pressure.

Learn to feel for the torque-curve of your engine. Highest revs does not always equate to fastest acceleration as torque falls off. Quicker acceleration is possible by shifting up a gear some way before 'peaking' towards the redline. As long as the next (higher) gear begins with revs in the engine's powerband.   

Coasting downhill in neutral uses more fuel (not to mention is unsafe driving practice). Modern fuel-injection activates total fuel cut-off while rolling in-gear with foot off the accelerator. At a rolling idle in neutral, fuel is required. 

Potholes and speedbumps: Best by far to anticipate, brake before, slow down and then the wheel can roll-on through. Not good to panic brake in the pothole because a 'locked-up' (even partially-braked) wheel will transmit more shock (and wear) through the suspension than a faster wheel left to loosely roll through.  (Besides excessive speed, braking mid-hole/mid-bump is one big cause of broken and prematurely worn suspensions.)

Pull hand-brake with foot-brake depressed. This minimises cable stretch and linkage wear, makes the hand-brake an easier pull to get pads against discs more firmly.

Observe same-axle wheels for more brake dust than others on your car. Feel the wheels (just occasionally) after a run for one (on the same-axle) warmer than others. This would suggest a binding caliper, wearing the brake, using fuel, dragging on performance. NB: Rears are normally cooler and less brake-dusty than fronts. 

Don't let fuel run down much past warning light. Starving and barely-immersed in-tank fuel pumps lack petrol to keep their bearings cool and minimise wear. 

Corrosion is your enemy always advancing. Often hidden. Dry garage as much as possible. Not good to garage a wet car - best to let it air-dry first. Otherwise not only are major surfaces wet, but also corroding damp and humidity can condense into every micro-aspect of the car while the whole can stay damper for longer. 

Turbo-chargers: Though not applying to our Jazzes, should be allowed always to cool off by running at 2000rpm or less for 30/40 seconds before engine switch-off. Otherwise lubricating oil around red-hot (perhaps glowing) bearings 'burns' leaving a carbonated grittiness on bearing surfaces ready for next start-up. (The single leading cause of eventual but premature turbo failure.)

Any untoward mechanical noise is never self-healing and may become much more expensive if ignored. Always be mechanically curious and questioning.

Stretching/skipping service intervals is ultimately very expensive. If appropriate, shop around for 'best value' - which is not necessarily 'cheapest' or 'dearest' .
 
Red dash warning lights for oil or water should be heeded immediately - always. Pull over, flashers on, slow down, stop, switch off, inspect... get professional help if need be.

Get into the habit of checking critical fluids under the bonnet. Every fill-up if need be. Be observant of any untoward drips (besides air con) on to tarmac/driveway/garage floor.

[John Ratsey]

How do you minimise the cold engine idle problem when it's necessary to defrost the windows (sometimes on the inside as well as outside) before safely driving away?

[guest1521]

Thanks John. This added:

"In very cold weather/winter, however, idle for a time may be necessary to clear fogged windows inside and out. Clear (all-round) vision is more important than any other consideration."

[guest4324]

 A few ways to save fuel:
 Make sure your tyre pressures are correct, should be at least the recommended pressure or adding 1 - 2 psi. Under inflated tyres greatly increases fuel costs.
 At higher speeds don't drive with your windows open too much, increased drag.
 If you have a roof box remove it when not in use, increased drag.
 Remove heavy items from the car if you don't need them there. (I mean what's in the boot and not parts of the car or the wife!!).
 Switch the air conditioning off if you don't need it.
 

[Pugsley]

This is a pretty substantial list full of wise stuff, some of which I didn't know, so thanks.  An observation however, if I showed this to my kids I'm not sure they would absorb/finish/read it in the first place (delete as appropriate)!!   Good luck with yours.

[culzean]

only one rule - acceleration and braking are the biggest thief of fuel, the harder you do either the more fuel you are using.  but try telling anyone under 25 that - good luck

[chrisc]

Try and anticipate when upcoming traffic lights will change

Otherwise, the OP's comments are very sound and are all common sense.

[VicW]

Try and anticipate when upcoming traffic lights will change

Otherwise, the OP's comments are very sound and are all common sense.

Shut the throttle well before you get to speed limit reduction signs,don't do what most people do,they get to the sign and then brake.
Time lost-negligible Fuel saved-noticeable.

Vic.

[UncleZen]

Minimise braking through maximum observation and anticipation. Saves brakes, fuel, mechanical stress

How does braking consume fuel?
As I understand it with modern fuel injection systems, the fuel is virtually cutoff when you lift your foot off the throttle, other than the amount needed to avoid a stall.
So unless your braking and using the throttle I cant see how braking could consume any more fuel than driving or accellerating.

[VicW]

Braking unnecessarily wastes fuel,hence my example of speed reduction signs and simply closing the throttle as you approach them.
If you maintain your speed up to the sign and then brake, the fuel you could have saved by closing the throttle is instead wasted by braking later.
The same applies when you approach slower moving traffic,why rush up to it then brake when all you had to do was close the throttle a bit earlier.
When the throttle is closed the fuel is shut off completely,the engine keeps rotating because it is still connected to the road by the transmission.When the revs drop to a certain level the fuel shut-off is reopened to keep the engine alive.

Vic.

[guest3735]

braking wastes fuel because you have to use more energy to return to a cruising or chosen speed than if you hadn't braked. energy is also lost kinetically (heat) when you bury the brakes.....as well as the cost of replacing the pads.
on the subject of which present F1 driver is best compared to prost.... i'd have to say button. conserves his fuel and tyres more and is smoother than most. just my 2p....

[UncleZen]

So, in effect, what you're saying is its your driving style that wastes fuel, not the braking per se.

[dg]

if I understand correctly, hard acceleration in itself is more fuel efficient than mild acceleration
http://en.wikipedia.org/wiki/File:Brake_specific_fuel_consumption.svg

so if one joins free flowing A road and needs to get up to speed there is no fuel saving in mild acceleration
one could argue that there is, by staying in sub-50mph for longer

but unnecessary hard acceleration that causes breaking in few minutes is obviously no good

only one rule - acceleration and braking are the biggest thief of fuel, the harder you do either the more fuel you are using.  but try telling anyone under 25 that - good luck

[dg]

also interesting to know how to gauge when engine is labouring
say I gained required speed, upshifted, barely touching accelerator, car mostly rolls, so I can maintain 1k rpm on GD with a/c off, possibly less, less then 800 rpm it struggles.
the moment I need to add power I'm forced to downshift naturally.
interesting if people with scanguage experimented with this

[culzean]

So, in effect, what you're saying is its your driving style that wastes fuel, not the braking per se.

if you could drive your car without ever using the brakes that would be the best thing ever for fuel consumption - every time you brake you are wasting energy,  and all it's doing is heating up your brakes and wearing them out.