Driving an automatic in the mountains: uphill, downhill and with a caravan

Driving an automatic in the mountains is easy and often more relaxed than a manual. Uphill, leave the gearbox in D and let it choose. Downhill, select a lower position (L, B, S or manual mode) before the descent so the engine brakes the car. Hold the car on slopes with the brake, never the accelerator.

Even so, gearboxes regularly play up on holiday. Long descents, a fully loaded car and a caravan on the back ask far more of an automatic gearbox than the flat roads around Utrecht. At ATR Transmissies in Montfoort we diagnose and repair automatic gearboxes every day, and the advice below comes from that workshop view: what the gearbox needs from you on the way up, on the way down and when something goes wrong far from home.

Is an automatic good for mountain driving?

Yes, an automatic is an advantage in the mountains. You do not have to work a clutch in hairpin bends, a hill start on a steep slope is easy with hill hold, and your attention stays on the road. Uphill, a modern automatic picks the right gear almost every time.

There is one catch. In normal D, many automatics change up to a high gear as soon as you lift off the throttle, so there is little engine braking. On a long descent you have to step in yourself and select a lower gear. If you do not, the brakes do all the work, the discs and fluid overheat, and your braking distance grows. Want to know how an automatic chooses its gears? Read our guide on how an automatic gearbox works.

How to drive an automatic uphill

Uphill is the easy part: leave the gearbox in D and press the accelerator smoothly. The gearbox changes down by itself when the engine needs more power. A few points help:

• Use steady throttle rather than repeatedly flooring the pedal.
• If the gearbox keeps hunting between two gears, select the lower gear in manual mode and hold it there.
• Higher revs are fine on a climb. Labouring in a high gear at low revs is harder on engine and gearbox. The Dutch motoring club ANWB gives a simple test: when you press the accelerator, the car should still accelerate easily. If it does not, change down.
• When you stop on a slope, hold the car with the footbrake or hill hold. Never hold it on the accelerator: that makes the clutch or torque converter slip and heat up for nothing.

On narrow mountain roads, ANWB adds that ascending traffic usually has priority over descending traffic, because it is harder to pull away again uphill.

How to drive an automatic downhill

Driving an automatic downhill comes down to one thing: engine braking. Select a low gear just before the descent, so the engine holds the car back and your brakes stay cool. As a rule of thumb, ANWB advises going down in the same gear you would use to climb that slope.

• Before a steep descent, switch to manual mode or select L, 2 or 3, depending on what your car has.
• Let the engine slow the car and accept that the revs rise. That is normal and does no harm.
• If you need to brake as well, brake firmly for a short time, for example before a bend, rather than dragging the brakes. That gives them time to cool between applications, as ANWB also recommends.
• Switch off cruise control and adaptive cruise control. ANWB advises this on climbs and descents alike.
• Never coast in neutral. The UK Highway Code (rule 122) warns that coasting removes engine braking, lets speed build up quickly and makes the footbrake less effective with increased use.

Which gear to use: D, L, S, B or manual mode?

Not every automatic has the same positions on the gear lever. These are the common ones and what they do in the mountains:

Not sure which positions your car has or what they do exactly? Check the handbook before you leave. Skoda’s Fabia handbook, for example, recommends the manual shift programme in mountainous regions. Reading it at home is much nicer than working it out halfway down a ten-kilometre descent.

Mountain driving per type of automatic gearbox

Every automatic gives engine braking once you select a lower gear, but the technology behind it differs, and so do the points to watch.

Conventional automatic with torque converter

The traditional automatic with a torque converter (the fluid coupling between engine and gearbox) is tough and copes well with mountain work. Its weak spot is heat. When the converter slips under heavy load, for example on a long climb with a caravan, the gearbox fluid heats up; prolonged slip can overwhelm its ability to get rid of that heat. Modern converters have a lock-up clutch that removes the slip once you are moving steadily. Uphill, use the engine’s power at healthy revs. Downhill, use manual mode, because in D this type of gearbox often changes up too early and the engine braking disappears. Read more about the torque converter.

CVT automatic in the mountains

A CVT has no fixed gears and keeps the engine in its best rev range on a climb, which works well. Downhill, a CVT increases engine braking a little by itself, but on a long descent that is not enough. Use the B position or L if your CVT has one, or manual mode with its simulated steps. With a caravan, stay within the towing limits in your handbook: the torque a CVT’s belt or chain can carry is limited by its design, so heavy loads above the rating wear it quickly. Read more in our explanation of the CVT gearbox.

DSG and other dual-clutch gearboxes

A DSG is safe in the mountains, as long as you avoid one habit: holding the car on a slope with the accelerator. A dual-clutch gearbox has two automated clutches instead of a torque converter, and creeping or holding the car on the throttle makes a clutch slip continuously. Skoda’s and SEAT’s handbooks warn that this can overheat the clutch. When that happens, the dashboard shows a gearbox overheating warning; stop, switch off the engine and wait until the warning goes out. So always use the footbrake or hill hold when you stand still on a slope, change down early in manual mode on climbs and descents, and take extra care with a trailer or caravan. More about this gearbox in our guide to the DSG gearbox.

Hybrids and electric cars

On hybrids and electric cars, regenerative braking does much of the work. ANWB advises using the strongest regeneration setting on descents. A full battery can switch off regenerative braking, so if you can, start a long descent without a fully charged battery. On many hybrids the B position adds engine braking as well.

Towing a caravan with an automatic in the mountains

An automatic is comfortable with a caravan in the mountains, but the extra weight changes the rules. The gearbox works harder on climbs and the engine has more mass to hold back on descents.

• Stay within the towing limit for your car and gearbox in the handbook.
• Change down earlier on descents than you would solo, and use manual mode on long passes.
• Watch for temperature warnings, and take breaks; ANWB suggests stopping every one and a half to two hours in hot weather.
• With a DSG, never creep or hold the car on a slope with the throttle, especially with a caravan.
• Hill starts with a caravan: hold the car on the brake or hill hold, then pull away smoothly in one go rather than creeping or holding the car on the throttle.

How to keep your automatic gearbox from overheating

You prevent overheating with fresh gearbox fluid, sensible driving and acting on warnings. Gearbox fluid lubricates and cools the gearbox, but it ages, and old fluid protects poorly under the heavy load of mountain driving.

• Have the condition of the gearbox fluid checked before you leave, especially if it has been in there for years. See our page on changing gearbox oil.
• Climb with enough revs and do not let the gearbox labour in too high a gear.
• Avoid creeping and slipping when pulling away, especially with a DSG and especially with a trailer.
• If the car warns that the gearbox is getting too hot, stop somewhere safe and let it cool before you continue. If the warning returns, have the car checked.

What to do if your gearbox plays up on holiday

Stay calm and do not force anything. An automatic that jerks, slips, shifts strangely or goes into limp mode (emergency mode) is protecting itself. In limp mode the gearbox usually holds one gear so you can still drive at low speed. Drive calmly to a safe place or a nearby garage, and do not keep going at motorway speed.

Switch off the engine, wait a moment and restart. Sometimes the warning disappears for a while, but the cause is still there. Note when it happened (hot or cold, uphill or downhill, with or without the caravan): that information helps whoever diagnoses the car. Find out what your symptom could mean in our article on a car that jerks or stutters or an automatic that does not shift properly. Not sure what is sensible on the road? Contact us, and we will help you judge whether it is safe to drive on or better to have the car recovered.

Before you leave: a gearbox check

Our view is that a mountain pass rarely creates a gearbox fault out of nothing. Heavy load and heat tend to bring out what was already developing: old fluid, a slight judder or a hesitation that nobody took seriously on flat Dutch roads. That is why we advise a check before a long trip rather than a repair afterwards.

Our approach is the same as for any complaint. We read out the gearbox, take the car for a test drive and, where needed, measure before we replace anything. If the fluid is old we advise a fluid service; if there is a fault, we repair what is actually faulty rather than replacing the whole gearbox. You decide after the diagnosis. Good gearbox maintenance prevents most holiday problems.

Are you a garage preparing a customer’s car for the Alps and seeing a gearbox fault you cannot place? With ATR Remote we can join the diagnosis at a distance.

Frequently asked questions about driving an automatic in the mountains

Are automatic cars better on hills?

In most ways, yes: there is no clutch to work on hill starts or in hairpins, and the gearbox picks the right gear uphill. The catch is the descent. In D many automatics give little engine braking, so you need to select a lower position. A heavily loaded automatic can also get hot on a long climb.

Should you downshift when going downhill in an automatic?

Yes. Use a lower gear than D: L, 1, 2 or 3, B on a hybrid, or manual mode with a low gear selected. A good rule of thumb is the gear you would use to climb the same slope. The car should slow down when you lift off the accelerator; if it does not, change down.

Should you put an automatic in neutral going downhill?

No. In neutral you lose all engine braking and have to scrub off every bit of speed with the brakes, which can make them overheat and fade. You also have less control when you suddenly need to react. The UK Highway Code warns against coasting for exactly these reasons.

Is engine braking bad for an automatic gearbox?

No. Engine braking is a normal part of how an automatic works, and the higher revs on a descent do no harm. It is far better for the car than overheated brakes. What does harm an automatic is heat from slip: holding the car on a slope with the throttle, or labouring in too high a gear uphill.

How do I drive an automatic car on a steep hill?

Hold the car with the footbrake or let hill hold do it, select D and press the accelerator smoothly as you release the brake. The automatic pulls away without fuss, even on a steep slope. Never hold the car still with the accelerator alone, especially in a DSG.

Which gear is used to climb a hill in an automatic car?

Usually just D. The gearbox changes down by itself when the engine needs more power. On a very steep or long climb, or with a caravan, select a lower gear in manual mode or L, 2 or 3 so the gearbox stops hunting between gears and the engine works at healthy revs.

What kills automatic transmissions?

Heat, mostly. Old fluid that no longer cools and protects, slip from holding the car on a slope with the throttle, labouring in too high a gear with a heavy load, and driving on with a warning light all shorten a gearbox’s life. In the mountains these come together, which is why fluid condition and driving style matter there.

Can you tow a caravan through the mountains with an automatic?

Yes, and an automatic is comfortable for it. Stay within the towing limit in your handbook, change down earlier on descents, watch the temperature warnings and never let a DSG creep on a slope. Have the gearbox fluid checked before you leave.

Ready for the mountains

With the right position, engine braking and fresh gearbox fluid, driving an automatic in the mountains is relaxed, whether it is the Alps, the Pyrenees or the Ardennes. Not sure your gearbox is ready for the trip, or did a complaint start on the way? ATR Transmissies in Montfoort diagnoses, maintains and repairs every type of automatic gearbox. Book your car in with your registration number and complaint, and head for the mountains with peace of mind.