Diesel is the new petrol, thanks to science and technology

Hello Baraza

For years, people have always had different issues on petrol and diesel engines. Some say diesel cars do not perform like petrol ones, they do not last long and are more expensive to maintain. Please clarify this issue for me in respect to the questions below:

1: I’ve always thought that car performance is determined by the power output of an engine and therefore would argue that a car with a two-litre diesel engine with an output of 163hp would be faster than a car with a two-litre petrol engine but with a 150hp power output. Am I wrong?

2: Taking into account two similar vehicles, one with a diesel engine and the other with a petrol engine, does it mean that the diesel engine vehicle will have a higher maintenance cost?

3: I’ve always been of the view that diesel engines are more efficient on SUVs rather than sedans, but these days there is a great number of sedans powered by diesel engines. What is your take on this?

4: At what point would it be effective having a diesel engine vehicle rather than a petrol one? That is, from what engine capacity would one rather go for a vehicle with a diesel engine?

5: I’ve seen lots of SUVs with diesel engines that have had long life spans. Is it true that their petrol engine counterparts would last much longer?

Kind regards,

Ndung’u.

I see the old argument is back.

1. You are right, generally. The higher the power output, the better the performance. To put this in perspective: Top Gear’s Jeremy Clarkson once demonstrated how a Skoda Octavia Diesel out-dragged a Volkswagen Golf GTi Mk IV over the quarter mile, and by quite a margin.

His point, however, was how bad the Golf had become, but our little discussion here applies too. A diesel car can be faster than a petrol car of similar capacity; if the diesel car’s power output is higher.

Other factors that determine these disparities in performance in vehicles of similar engine capacity are gross vehicle weight and gear ratios in the ‘box.

2. Again, generally yes; more so if that diesel car has a turbo also (as is common nowadays). This is down to the use of heavier (and sometimes bulkier) components that can withstand diesel torque and the application of high pressure injectors in the engine. They also have shorter service intervals.

3. My take on this is that diesel power can be used almost anywhere now. In fact, diesel engines are so developed that major races (Le Mans 24 Hours and Dakar, for instance) are now being dominated by diesel-propelled entries, in a history plagued by petrol victories.

The development of diesel engines is such that they are as smooth as, and as powerful as (if not more than) their petrol equivalents. This is due to turbo technology and material science.

Diesel engines have the added bonus of having good economy and low emissions, which is why they are finding their way into small cars, with incredible success. In France, more than half of the cars bought, irrespective of size or class, are diesel-powered.

4. From Point 4 above, any. Engines range from as small as the 1.0 litre 3-cylinder turbo in the VW Polo BlueMotion to massive units such as the 6.0 litre V12 TDI in the Audi Q7. These are just road cars.

Trucks have engines as huge as 16,000cc V8s, then we have trains, ships, earth-moving equipment…. There is no limit to size for diesel engines nowadays.

5. This greatly depends on how they are (ab)used.

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Hello Baraza,

I drive a Toyota Probox and would like to know how you rate this car in terms of speed, stability on the road and fuel consumption. Second, the fuel gauge is not working and it’s thus difficult to tell wether the car has enough fuel or not. What could the problem?

Eric.

The Probox’s speed is typical of Japanese econo-box cars: nothing special, in spite of what people may say (this includes those who will tell you that nowadays these things are used to transport miraa).

If and when you get to 180 km/h the car will stop accelerating. Japanese cars have a limiter set at this speed. Stability on the road is not the best either, especially given that the car is a bit tall and some use leaf-spring rear suspension.

Fuel consumption is good though, if you avoid trying to clock maximum velocity all the time. I’d say 10KPL is the worst reading you’ll ever get, but 16KPL is possible with sensible driving.

About that fuel gauge: eliminate the usual suspects first. Check to see the wiring in the dashboard is in order. These are the other common causes:

1. Defective Dash Voltage regulator (voltage limiter) or gauge

2. Loss of ground/earth at the sending unit

3. Break in the wire going to the dash

4. Bad Sending Unit

5. Fuel gauge itself is defective

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Hi Baraza,

I’m planning to buy a 2005 Pajero IO. I like the boxy look and whatnot, but I’ve been discouraged by those who say it has a high fuel consumption and its GDI engine is problematic.

If I decide to go for it anyway, should I buy one with an automatic or manual transmission? Plus, what is its off-road capabilities and comfort?

Mark.

As for whether to buy manual or auto: that is entirely up to you. Which do you prefer? I would go for the auto myself (that is not saying much: there is nothing to nominate the auto over the manual, I just prefer autoboxes on such cars).

Off-road capabilities: I’d give it a “Lower Fair”, on a scale of Poor – Average – Fair – Land Rover Defender – Mountain Goat. Maybe 5.5 out of 10, where 0 denotes a Lamborghini Aventador and 10 is a Rhino Charge-spec off-roader.

Off-Road Comfort: I’d give it a 2.5 out of 5, where 0 denotes maximum likelihood of car-sickness (vomiting due to the bounciness or the need for physiotherapy due to rock-hard ride.

It’s a little of both, actually and 5 is the point where you can’t tell if the car is off or on road, such is the smoothness (2013 Range Rover).

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Hello Baraza,

Thanks for the good work you are doing. I’m writing to make a rather unusual enquiry: I have a budget of just Sh200,000 for either an old 1.3-litre local Nissan B12, a Toyota AE86 or 90, or a Duet which I will use to cover a distance of 20 kilometres daily to work and back. Bearing in mind that I have never owned a car before, kindly tell me which of these, or any other, would suit me.

Thank you.

I was reading through your e-mail until I go to the point where you mention an AE86, and my eyes turned misty. Where can I get a Hachiroku for 200k? I definitely want one of those.

Maintenance and economy of course favor the Duet, but a Duet going for 200k is not likely to be a wise purchase. There must be something seriously wrong with it.

It is thus a close race between the B12 and the AE90 (the B12 was the last good Nissan Sunny car we saw for the longest time. Later models were rubbish), but I would say the AE90, especially if it is 1.3 like the Nissan.

The 86 Corolla might not be as economical as the others (the difference is negligible anyway), but it is a damn good car to drive.

Where can I get one for 200k?

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Hi Baraza,

Thank you for the wonderful job you are doing. I had a petrol Isuzu Trooper 2 and a Toyota Sprinter K25 which I have liquidated in order to acquire the old box-type Prado.

I would like to know the cons of this car since I made the mistake with the Trooper, which once guzzled Sh20,000 in fuel from Nairobi to Mombasa and back.

This time I don’t want my December journey to the coast to become a nightmare again, so your advice would be greatly appreciated.

Thumbi.

The only con I can think of is that the Prado does not corner too nicely, but then again, this is not a car built for cornering. The box shape is also aerodynamically inefficient, but if you got one with a diesel engine (a well maintained one), Sh20,000 worth of fuel to and from Mombasa will be confined in the dark chasms of unpleasant memories and life’s hard lessons.

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Dear JM,

I am looking forward to purchasing two cars in the near future, kindly enlighten me on the following:

The first is a family car (madam, two daughters and I) to be used within Nairobi and going to Nakuru once in a while. I am torn between a Honda CRV, a Nissan X-Trail, and Volkswagen Tiguan, all local and manual versions. Which of these is the best in terms of performance, comfort and safety?

The second is a personal car for use within Nairobi. I am again torn between two versions of the same model, Mitsubishi Lancer GLX or EX.

Again, in terms of performance, comfort and safety, which is the best? I am made to understand that the Lancer EX comes in two versions, which is the best? The sport or the ordinary one?

Lastly, I prefer manual cars after near-death experiences with automatics. In a manual car, I feel more in control compared to autos, where one just sits ‘there’. Do manual cars have any distinct advantage over their cousins?

Performance may favour the X-Trail in the first lot, but only if it is the X-Trail GT. Otherwise, the Tiguan may be faster. And safer. And more comfortable.

For the second lot, the EX may be better than the GLX in comfort. Performance and safety is the same (it is the same car, after all, with different trim/specs). Of the two Lancers, I would opt for the GT, mostly because Mitsubishi tells us it is sporty, and it does look like an Evo X. I know these are not sensible reasons for choosing it, but hey: we all have our own peculiarities.

Manual cars offer better control (as you point out) as well as slightly improved fuel economy and marginally better performance.

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Hallo,

Thanks for your good work. I wish to take you back to the old-school era and I hope you will assist because, hey, we deserve your attention too!

I have driven a Peugeot 205 for 10 years, initially an 1124cc and later 1.4 which actually is 1360cc and the performance of the latter is above-average, except for suspension issues. I have two issues, though, that require your help:

1: How can I fix gear number two in the 1.4, which makes a loud sound when slowing down but all smooth when the car is stationary? I hear this is a common problem with these cars.

2: Any advice on dealing with suspension issues, especially on stabilisers and bushes, would be much appreciated.

3: How would you rate the 205 against the 206 and the Toyota Starlet?

Regards,

Joseph.

1: You are right, 205s suffered from jumpy drivelines, and this problem was most pronounced in the GTi. However, I suspect you may also be downshifting a bit early. A 405 I once had also did not favour early downshifts.

Try this: when slowing down, wait until you lose as much speed as possible (with the clutch engaged, wait until engine speed dips to 1,000 rpm or less) before shifting down. Tell me if there is a difference.

2: Yes. Change them when they go bust, and only use genuine parts. Avoid cheap fakes (or expensive fakes, for that matter, if they exist).

3: I sort of prefer the 205 to the 206. The 206 looks too girly and I have a thing for old-school, bare-knuckle, no-frills driving, which is what the 205 offers.

The 206 is more modern, softer, heavier, more mild and generally… feminine. Compared to the Starlet… well, they are very similar in terms of utility. The Starlet may be more practical though because it has a wider opening hatch at the back compared to the 206.

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