CAR CLINIC: Choosing between petrol and diesel cars

Petrol engines are great in consumption and reliability but if you take good care of the Diesel engine it will serve you effortlessly. PHOTO| FILE| NATION MEDIA GROUP

What you need to know:

  • Stick to reliable stations, irrespective of engine type and how fuel is delivered into the said engine.
  • Consumption for the petrol engine will be generally higher compared to the diesel one, but the petrol engine will be both more reliable.
  • Take good care of the diesel and it will serve faultlessly; I have a friend who has a diesel Pajero with 250,000km on the clock and it has never really bothered him outside of the usual niggles.

Hi Baraza,

Many thanks for your previous response. I will take Pajero. However, I’m stuck again between petrol and diesel engines. My mechanic advised me against taking the diesel engine. I have a D-Max with common rail transmission, which is the same as Pajero so long as one fuels in a reliable station. I am not sure about petrol engines. Kindly shed light on consumption and reliability. Rotich

Hi Rotich,

Strange sentiment, this: “ … which is the same as Pajero so long one fuels in a reliable station”. What do you mean? Are you implying that if one goes to an unreliable station the engine (and NOT transmission) stops being a common rail? Does it transform into direct injection?

Anyway, stick to reliable stations, irrespective of engine type and how fuel is delivered into the said engine. Your mechanic discourages you from a Pajero diesel because this belongs to that class of susceptible engines that will quickly be brought to heel when fed port rather than the house wine — figuratively speaking, of course; I’m not implying that one can run their compression ignition mill on potables.

Consumption for the petrol engine will be generally higher compared to the diesel one, but the petrol engine will be both more reliable — also generally — and cheaper to maintain if it comes to that.

However, take good care of the diesel and it will serve faultlessly; I have a friend who has a diesel Pajero with 250,000km on the clock and it has never really bothered him outside of the usual niggles that one comes to expect from a car that has covered two-thirds of the distance from the earth to the moon.

Mitsubishi Pajero. PHOTO| COURTESY

In motorsports, ability always trumps wallet size

Firstly, I would like to appreciate the vast knowledge you have on cars and taking the time to guide us. It is truly a noble cause you do. I would rather be caught dead (figuratively speaking) than fail to read the Car Clinic. God bless you abundantly.

I recently bought a 2.0L turbocharged manual Subaru Forester Sf5 year 1997 with a little money to spare for modifications in terms of drive train, transmission and suspension.

I am planning to use it during the weekends as I have another car I use daily (Honda Fit). I thought I had everything figured out until I had it in my arms and now I feel like I have no clue where to start.
I am a huge car enthusiast and I wish to join the Kenya motorsports scene. It has been a lifelong dream to be in motorsports and to feel that adrenaline rush. I therefore come before you oh great and wise one seeking your solemn wisdom in terms of modification generally and specifically with regards to my Subaru. Mbugua Mburu.

Hello Mbugua,

It is nice to hear from a true enthusiast. Now, let us get into it.

You may or may not have heard of the late Amir Mohamed. Great man, very wise and a car modifier extraordinaire. He had plenty of sage advice to give those in pursuit of builds and those of us fortunate to be in his circles benefited a lot from it.

He was a firm believer in ability over wallet size. He always insisted that those he cared for (us, in other words) first learn to master their vehicles before rushing into modifications whose fury we may not be able to fully harness anyway, despite the amount of street cred one may glean from the celebrity status of having pumped GDP-level cash amounts into under-skin enhancements — and probably have nowhere to sleep as a result. Priorities are important. To swim well, you must first learn how to float.

There is no substitute for seat time in the pursuit of a Masters in Car Control — which is why the late Paji was such a brilliant driver.

First bring yourself to within or slightly beyond the dynamic limits of the Sf5 in its current form before upgrading it. You should be able to drive the tyres off that car, almost literally, before you think of turning up the wick.

Can you slide it? Can you kill understeer at any speed and in any corner of whatever severity? Can you use the symmetrical AWD to power yourself out of oversteer? Can you induce any of these things? Can you trailbrake? Can you turn the car on a dime? Have you cleared the clock in it without sweaty palms?

[We interrupt this programme to bring you a public service announcement from the Global Road Safety Partnership initiative. Do NOT practise any of these manoeuvres on a public road. Never. Find a field somewhere, or a disused airstrip. An empty parking lot, even — anywhere you will not come into contact with anybody else and you cannot really hurt yourself besides bruising an ego. I cannot stress enough how important this is. The facilities are there; you just have to know where to look and improvise with what is available … but do NOT practise on a public road]

So, you are now in full control of your car. Start bringing the power up smoothly through a staggered Stage 1 tune. Stage 1 tune consists of relatively simple modifications and adjustments to things like the intake and timing, exhaust and ECU map. These can be done singly since they mostly don’t affect other parts of the car.

Subaru Forester. PHOTO| COURTESY

As the power steadily increases, you may want to think about bigger tyres and brakes, or else your car just might toss you off the road from an overwhelmed running gear.

Of course as you slowly ascend the horsepower ladder, you need to maintain a grip on your steed’s reins. With each power level, ensure you stay on top of things by being still able to fully control your car in all situations.

If you ever get to a power level where the car slides too much or “runs away from you”, this is where you now spend more time and mental resources rather than money. You either need more talent or your build at this point needs fine tuning to work properly. From there proceed to Stages 2 and 3 (these differ from Stage 1 in the complexity of the modifications and the costs but it is the same protocol as Stage 1, more or less).

You get the picture. Grow your skills along with your car. I am a firm believer in raw skills over tax bracket. That is why I use my office as track impresario at Club TT Motorsports to place an emphasis on the auto-test (a.k.a “gymkhana”) over the drags — in which a nine-year old in a Dodge Demon could easily carry the day provided s/he keeps the car pointed in the right direction — and this is in spite of the overwhelming popularity of straight line work.

There is driving and then there is driving: anyone can dial in a spectacular time on a strip if they have the wherewithal to pony up for a dragster, but real drivers can manhandle corners into straights and make their cars to submit to their will even in an inferior chariot. A true legend is one who can turn the tables on their opponent in disadvantaged circumstances.

In a drag race, things follow a more hip hop-ish timeline: Money, Power, Respect. I do not buy into that.

Speaking of drags, I usually execute an unforgiving format whereby mistakes do not go unpunished and second chances are damn-near nonexistent.

A good driver has his wits about him at all times and will do his damnedest to stay ahead of his opponent until the laws of physics take over and raw horsepower dominates whatever housefly reaction times an opponent may possess. Drag addicts beware: I take no prisoners.

Of course, if you are in a bit of a hurry you could skip all that I have written and simply write a big cheque to an overseas tuner who will ship a fully developed race engine to your address for you to slay with, but where is the fun in that?

You will also be facing a steep and potentially painful learning curve trying to corral all those hundreds of wild rampaging horses with your yet-to-be-honed talent.

Whichever path you choose, you do have a few options to stretch your legs as far as local motorsports go; and, not to toot my horn, but the easiest and best way to exploit that SF of yours under the aegis of a motorsports umbrella would be to come perform at the circus in which I am ringmaster: Time Trial Motorsports.

I will be waiting …

When in doubt about what dashboard alerts mean, try this …

Hello Baraza,

Thanks for the airbag alert you provided on Car Clinic of August 15. On that note, please educate us on some of the common alerts that we find in our cars as some of us have no clue what they mean. Sometimes one has to get a mechanic who may or may not accurately establish what the alert is all about. I have an alert for the handbrake that has not disappeared despite having mechanics check on it on several occasions. Joyce.

Hi Joyce,

Yeah, I’ll have to sidestep this one because it varies from car to car. While there has been a steady standardisation of dashboard warning lights over the years, we are still very far from having a universal chart we can refer to that applies to all vehicles.

Volkswagens use colour coding to determine the severity of the warning light. The BMW E34 that joined the family recently spells out the problem in truncated English via a two-colour dot matrix display in the speedometer circle.

The Land Rover Discovery 4 has warning lights I have never seen in another car, ever. Should I break this down brand by brand, and how long will it take before you as a reader zones out — especially after we are done with your car and you think “The odds of me driving a MAN HB4 D20 Common Rail triaxle passenger bus are very low, why do I need to learn about what its dashboard lights mean?” See where I’m going with this?

This is the point where the most sensible word would be RTFM: Read The [Bleeping] Manual. Most cars have them (bleeping manuals), those that don’t may require a jaunt down an internet rabbit hole to find one in soft copy, in forums where you may or may not have to weather a fair amount of abuse before receiving satisfaction, but those forums are a good place to start.

Alternatively, Google is your friend. Try something called a “reverse image search”.

Of swapping engines and changing your car’s suspension, brakes

Hello Baraza,

I have a Mitsubishi Pajero old model 2.5l diesel engine. I would like to change to either a v6 or 4 straight engine but with a higher fuel efficiency and more engine power. My question is, would I have to consider changing the suspension and brake system since the engine will be producing more brake horsepower? Or with swapping the engine, will the brake system be able to handle the speed? Richard

Hi Richie,

No, you won’t need to change the suspension or brakes … or come to think of it, perhaps you do. Let me talk about another vehicle, the “all-new” Land Rover Discovery.

I did a review on it sometime last year and I remember writing that we were specifically asked not to call it the Discovery 5, but rather “the all new Land Rover Discovery” — which was fine last year, but what about now? Is it still “all new”? I digress.

Something else I observed in the review was that the diesel version of the vehicle rode a bit harder and harsher compared to the petrol one and a fellow autojourno and I surmised that it could be because the diesel block is heavier than its petrol stablemate, so it weighs down the front suspension a bit more, leaving less stroke room for the air suspension to work with.

The braking on either vehicle seemed good enough, though. Our suggestion to the manufacturer was to recalibrate the front suspension of the diesel car to factor in the increased weight of the heavier engine. It was nothing critical but it was observable, which is saying something.

So, you don’t really need to change the suspension and brakes — after all, you are currently on a diesel engine anyway — but if you do the swap and notice a difference in how the vehicle’s road-holding and comfort levels feel, then you may need to do something to your front suspension. But no, it is not.

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