The Doctor

AUDI DIESELS GOING VEGGIE

Dear Doctor, I’m sure you’ve read Audi’s announcement that some of its diesel engines have been approved for renewable fuels. This is of greater interest to me than the development of yet more electric vehicles, but I’m worried that these things tend to get lost down the back of the sofa. A reduction in CO2 emissions of between 70 and 95% compared to fossil diesel should not be ignored and I applaud Audi for its efforts. Or are you going to chuck a spanner in the works and declare it a PR stunt? I look forward to your response. Tom Heathcote

Dear Tom, Don’t worry, I’m not about to pour vegetable oil on your parade. For the benefit of readers who missed the announcement in the last issue, Audi has approved many of its current six-cylinder diesel engines for use with HVO (hydrotreated vegetable oil). This renewable fuel allows diesel engines to operate in a more climate-friendly manner and there are few downsides. You’re right about the reduction in CO2 emissions, but I’ll add the following quote from Matthias Schober, the head of powertrain development at Audi. He said: “As the cetane rating of HVO is around 30% higher, the combustibility of the engine is enhanced. The positive effects of this are particularly noticeable when cold starting. We tested the effects on various components, the performance, and exhaust emissions in validation runs before granting approval.”

HVO uses residual and waste materials, such as waste cooking oil and residues from agriculture. The use of hydrogen turns the oils into aliphatic hydrocarbons, which makes them suitable for use in diesel engines. It can be used as a standalone fuel or in conjunction with regular diesel. All good stuff, then, but it’s worth noting that HVO is nothing new. Indeed, it has been approved for use in Audi’s four-cylinder diesel engines since June 2021 and is very popular in Scandinavian countries. As a biofuel, it has been around for 15 years or so.

Consumer awareness is low in the UK, although HVO has developed some traction within the agricultural industry. There are around 600 filling stations in Europe, but you’ll struggle to source it in the UK unless you’re happy to have it delivered by a tanker! It’s also around 20% more expensive than regular diesel, although this is far from extravagant for a clean fuel. Another downside is the threat of deforestation to grow the fuel, although the use of waste materials will minimise the impact.

Did you see that BP has acquired a 30% stake in the UK’s largest HVO producer? Green BioFuel has produced more than 55 million litres of HVO over the last two years, but BP’s intention is to support the decarbonisation of construction, freight off-road and marine industries. Unfortunately, private consumers aren’t included in this vision, but I guess this is due to a classic ‘chicken and egg’ situation. Audi says it will build its last combustion engine in 2033, so is a shortterm fix. That said, it could enable diesel cars to remain in use long after electrified cars have become dominant – let’s hope that the policymakers and environmentalists recognise the positive effect of biofuels like HVO. The Doc

SANTA FE DELIVERS THE GIFT OF DIESEL

Hello Doctor, Do my eyes deceive me, or is the Hyundai Santa Fe diesel back on sale again? I know my sight and memory aren’t what they used to be, but I could have sworn the diesel version was axed last year, or is my mind playing tricks on me? It’s listed for sale on the Hyundai website, but this could be a hangover from last year. I only ask because I’ll be looking for something new to tow my trusty Coachman, and a Hyundai Santa Fe diesel would fit the bill. Do you know why Hyundai has made a U-turn? Are diesels back in favour with the brand? All the best, Robert Dempster Langley, Berkshire

Hello Robert, Nice to hear from you again after many years. You’ll be pleased to know that your eyesight hasn’t deteriorated since you last got in touch, although I fear you missed a small chunk of issue 422. You’ll note that this magazine was the first to report on the return of the 2.2-litre CRDi versions, with our editor calling it “a welcomed U-turn in policy”.

A little bit of background for you. The new Santa Fe arrived in the second half of 2018, at which point the 2.2-litre diesel was the only available engine. Most road testers agreed that the revamped CRDi unit was refined, economical and perfect for a large family SUV. It’s now fashionable to axe diesel engines, so the CRDi unit was dropped as part of the 2021 facelift, leaving only hybrid and plug-in hybrid powertrains as options. Great for ticking green boxes, not so great if you’re after a punchy and reliable engine for heavy loads and towing. The maximum towing capacities of the electrified versions are woeful, ranging from 1,350kg for the plug-in hybrid, up to 1,650kg for the standard self-charging hybrid. This incensed the towing community, which left Hyundai in danger of losing customers to Kia; the Sorento uses the same 2.2-litre CRDi engine.

The figures are reassuring: 199bhp, 325lb ft of torque, 2,500kg maximum towing weight and 100kg nose weight. All diesel versions come with an eight-speed automatic transmission and four-wheel-drive as standard. You’ll pay £42,160 for the Premium trim or £45,455 for the Ultimate model. Not cheap, then, and you’ll also have to pay the premium surcharge for Vehicle Excise Duty (VED).

You ask if diesel cars are back in favour? I suspect not, but this is an example of manufacturers blindly pursuing an agenda without listening to their customers. The towing community still relies on diesel engines, so removing them altogether had the potential to upset a lot of people.

I hope this helps, Robert. May you enjoy many happy years to come in your Coachman. Best regards, Doctor

DAVID PRICE IS RIGHT

I have just finished reading the February issue of Diesel&EcoCar magazine, especially the piece about smart motorways. A large number of people hate or detest them without, in my opinion, a logical reason.

What is the difference between a smart motorway and a dual carriageway? Very little and yet I haven’t heard anybody complaining about dual carriageways!

Both types of road are basically the same. The dual carriageway has two lanes (usually), whereas the smart motorway has four (normally). Both types of road have a 70mph limit, so no difference there. Neither has a hard shoulder, so no difference there either. The dual carriageway also allows agricultural tractors, mopeds, cyclists, and learner drivers, all of which increase the hazards, and yet smart motorways are ‘dangerous’ according to some people. Perhaps it is the lack of available refuge areas in the event of a breakdown?

When I was working for a living, I used the A50 dual carriageway between Stoke and the M1 several times a week. On the stretch of road between the roundabout after you exit the 40mph limit from Stoke, to the roundabout just before you reach the M1, there are four laybys, three roundabouts, 12 exit roads and one service area on that 40-mile stretch of road – a total of 20 points of safe exit off the carriageway. On a 40-mile stretch of smart motorway there should be, by law, between 40 and 53 refuge areas in case of a breakdown – that’s more than double the number of exit points compared to the average stretch of dual carriageway.

So, the smart motorway has four lanes rather than two, double the number of refuge areas, and no learners or cyclists etc, so why are they considered to be more dangerous by many people?

Over the past sixty years, motorways have become safer places to drive with central barriers, better lighting and signage etc, and we have become used to the fact that the road ahead will be clear because of the hard shoulder, an attitude we do not take with us when driving on a dual carriageway. Perhaps we should all realise that when a motorway becomes ‘smart’ a different driving attitude should be taken. Thomas Wardle

Hello Thomas, Ian kindly forwarded your response to the letters regarding smart motorways (issues 421 and 422). As your observations are concerning my column, I hope you don’t mind me responding on his behalf.

I’m grateful for your views on the subject; it’s great that the letter from David Price sparked some debate. The problem with the media coverage is that it’s all so black and white. What happened to balanced reporting and basic facts? Read an online article on the subject and the consensus is clear: smart motorways are evil. There are exceptions. A year ago, Hugo Griffiths wrote an excellent article for Auto Express with the headline: ‘Smart motorways are the safer option, we all need to look at the facts.’ I don’t agree with everything he said, but I can get behind his call for less emotion when debating the subject. He also made some excellent points regarding the aspects of motoring that are actually safer on smart motorways. I’d encourage you to read the article and the subsequent comments that were made.

As I tried to say in my original response to David Price, the positives of smart motorways cannot be ignored. The ability to lower speed limits to reduce congestion and maintain traffic flow is a good thing, as is the opportunity to close a lane or two in the event of an accident or breakdown. It’s also worth remembering that a smart motorway is cheaper and less environmentally damaging than a widening scheme. I also echo Hugo’s sentiments when he says that other roads are less safe. Rural roads are the most dangerous in Britain, accounting for more than half of all fatal crashes. Are there calls to stop people driving on country roads? Of course not. According to the charity Brake, ten times as many people die on rural roads than on motorways. The flipside to this, and the counter to your argument, is that it’s three times more dangerous to breakdown on a smart motorway than it is on a conventional one. This has tragic consequences for motorists and breakdown recovery operatives.

You make a very good point about the mix of vehicles using dual carriageways. There have been many calls to ban tractors from fast roads; just a few years ago, Highways England proposed to ban agricultural vehicles from ‘smart’ A-roads. Under the proposals, some dual carriageways would be converted into motorwaystandard roads in which vehicles enter via a slip road. Cyclists, pedestrians, horses, and mopeds would also be banned. Incidents involving tractors are few and far between, but when they do, they have devastating, and often very tragic consequences.

We know that the rollout of smart motorways is on hold until at least 2025. Announcing the pause in construction, the transport secretary Grant Shapps said: “While our initial data shows that smart motorways are among the safest roads in the UK, it’s crucial that we go further to ensure people feel safer using them. Pausing schemes yet to start construction and making multimillion-pound improvements to existing schemes will give drivers confidence and provide the data we need to inform our next steps.” My concern with this statement is that it links confidence with data. The reputation of smart motorways has been severely damaged, so it will take more than cold data to restore confidence. There have been too many tragic incidents for sceptical motorists to be won over, especially when the media is reporting it so black and white.

Three years is a long time, so the political, environmental, and social landscape could look very different in 2025. I’ll be watching the developments with interest. Best regards, Doc

H O W I T W RKS

EV Drive Modes and Eco Driving

When an electric vehicle driver is setting off, the driver needs to select an appropriate drive mode. There's a distinct lack of terminology standardisation as yet in driving options for electric vehicles, and in how they are selected, but most are self-explanatory, and use terms like Sport, Normal, Eco, and Eco Plus, with others for exceptional driving situations, like Snow. There may also be an option to select 2WD or 4WD. Usually the eco mode choice involves the deselection or dumbing down of energy hungry functions, like heating and climate control, that can affect driving range. If your battery gets down to a very low charge level, it’s best to leave it to the car, which will automatically adopt a progressively more severe economy mode, with throttle response and speed severely limited, and all but the essential services shut down.

Let's consider how the eco drive modes can help extend your driving range though. When you lift off the accelerator, without touching the brakes, there's a controlled deceleration that converts the car's momentum into electricity to recharge the battery. In many electric vehicles, the highest eco setting offers virtually one-pedal driving, slowing down to a standstill without use of the brakes. But not everyone likes the strong deceleration of such settings, and there are other ways to boost your battery range. By adopting much the same skills as used in diesel or petrol fuel economy driving, any driver can get better battery mileage with a little thought and effort. So, how do you set about achieving this?

It all begins before you set off though, where the pre-conditioning options of your electric vehicle are vital. You can get many more miles from a charge using charging settings that use mains power to defrost, or pre-heat the cabin, and maybe the heated seats, or even cool the cabin in hotter weather before you set off. Some also have battery heaters for cold weather, but if not, you should set your charger timing to finish an hour or so before you plan to set off, leaving the battery still warm, and optimising its range. Another obvious tip is to keep your car under cover, either to keep it warm, or cool, whenever you can. Every kWh that you can draw from the mains, rather than the battery, gives you another 3 to 4 miles, and that can put as much as 40 to 50 extra miles on your range, particularly in winter weather. When you are driving, economical use of the heating and climate control system increases driving range significantly, so do check the owner’s handbook for the best ways of doing this.

When driving on motorways and dual carriageways, cruising speed is hugely important. Cruising at 65 to 70mph, as against 75 to 80mph, will give you 25 to 30% more miles for every kWh stored in your battery. On longer journeys, the time lost by cruising at a lower speed can often be recovered as you won’t spend so long charging at a motorway services area, for instance. Most electric vehicle drivers will benefit from using adaptive cruise control, that maintains a steady speed and a consistent distance behind vehicles ahead without any braking. In stop-go congestion, using automated systems like Traffic Jam Assist will save you more fuel than any human skills can, and helps cut the risks of a low-speed accident. On busy A- and B-roads you can, of course, choose to use the high energy recovery settings, but you will need to perfect the art of feathering the accelerator to smoothly moderate the deceleration to suit the conditions, using the car's momentum to coast down to a stop, rather than screeching to a halt. Better still, looking well ahead, and gently easing off the accelerator to buy time for traffic lights to turn green, or roundabouts to clear, can gain you lots of extra miles. The car's momentum is better utilised without even using the energy recovery system, which is, it's worth remembering, at best, only around 65% efficient.

The whole business of eco driving is largely a state of mind. If you're comfortable with the techniques of driving a petrol or diesel car economically, you'll automatically take the same approach when you drive an electric vehicle, and soon master the key differences. Smoothness of progress is always beneficial, as does keeping a good distance between your car and other road users. Jerky progress, using strong acceleration, and/or hard braking will waste precious miles of range. The performance potential of many of today's electric vehicles is a temptation that should mostly be declined to achieve the optimum driving range. But when you see a clear road ahead and are planning to accelerate up to a good cruising speed, it's a good time to draw on the electric vehicle motor's meaty torque and enjoy some really hard acceleration without wasting any energy!