In Summary
  • Now that you want to dabble in the premium luxury that BMW offers, go the whole way and get the 5er.
  • It has always been BMW’s definitive vehicle and is the one shown the most love by engineers.

Hey Baraza,

Great job in your column, I am an avid reader of your articles . Your analysis is always incisive.

My question is simple: I am trying to choose between a 2009 BMW 320i M Sport and a 2009 BMW 525i M Sport. While the 3 series is cheaper, with almost similar amenities, the 5 series seems  larger and more executive.  I am coming from a 2007 Subaru Legacy.

What are your thoughts on both cars? The one I choose should serve me reasonably well for three to four years.



When you are walking on thin ice you might as well tap dance. Now that you want to dabble in the premium luxury that BMW offers, go the whole way and get the 5er. It has always been BMW’s definitive vehicle and is the one shown the most love by engineers.

Does buying a 504 today make sense?

Hi Baraza,

I  had the privilege of growing up in a house with a second generation Isuzu Trooper (2001) and a Peugeot 504 that was bought around the same time I was born in the early ’90s. Sadly, I never got to drive the 504 after getting my licence because it had been sold but the Trooper is still around. Would you recommend that I buy a 504 when I have the money or should I just move on to newer, more fuel-efficient and tech advanced cars? (I find the Trooper a beauty because I like manual cars but the consumption is crazy).

David G.


Hello David G,

Move on to newer, more fuel-efficient and technologically advanced cars. A 504 from the early ’90s is not your friend, agemate notwithstanding. It has few amenities if any, no creature comforts and is thirsty, not to mention environmentally unfriendly. Also, expect infirmity at frustrating levels once it begins to show its age, and it will show its age because it’s old. This car is not your friend.

There is a massive disclaimer to my comments above, though. If you chance upon one in pristine condition then by all means go for it. The vehicle has a distinctive design, is extremely comfortable and it purrs like a kitty when stroked in the right way. This will make a very good collector’s car, the operative words here being “collector’s car”; but the flipside is you will have your work cut out keeping it in shape. It is not recommended for daily driving; the risk to its integrity and the associated costs= of keeping that integrity intact is too high.

Get something contemporary for starters, then save up for a 504 as a second car.


What if we could fill car tyres with nitrogen


Thanks for your informative articles.

If you compare plane and car tyres, plane tyres are filled with nitrogen and not normal air that is readily  available at gas stations and roadside yards where motorcycles are repaired. This is because nitrogen does not expand and the tyres rarely blow. Is there a way a car tyres can be filled with nitrogen and avoid tyre burst-related accidents and incidents. Is this possible or is nitrogen too expensive?



Hello Brian,

Yes, there is a way that car tyres can be filled with nitrogen and that is by visiting one of the gas vendors such as BOC and asking them for nitrogen. It is that simple, but it might or might not be cheap. I don’t know how much nitrogen costs and whether it is sold by mass or by volume at STP (standard temperature and pressure).

What I know is filling your tyres with nitrogen is an overkill. Only one car comes standard with nitrogen-filled tyres and that is the Nissan GTR. But then again, the GTR is a 315km/h, 1,800kg car that does 0-100 in less than 3 seconds, and whose cornering abilities are so violent that the rims have special grooves to hold the tyre bead to prevent the tyres from getting torn off their moorings when turning hard. Such a vehicle might, indeed, need nitrogen in its tyres since the whole idea behind using nitrogen is its inertness and insusceptibility to temperature fluctuations. A car that can rip its tyres off its rims is going to undergo a lot of temperature fluctuations when driven the way it was engineered to be driven.

Plane tyres are filled with nitrogen for slightly similar reasons, though nobody does any hard cornering with aircraft while taxiing on tarmac. Planes fly very high where it gets very cold (to below freezing, actually) and the air in the tyres loses volume (Charles’ Law) or even condenses into a liquid form. This means the tyres can collapse to the point of unseating themselves from the rim and the air escapes, giving the aircraft a flat tyre while aloft, which should make the present tense at landing time. Speaking of landing time, some of these aircraft weigh as much as 300 tonnes and have to slow down real quick from a touchdown speed of around 280km/h. That is a lot of stress for a tyre and it generates a lot of heat... the same tyre that moments before had been stowed away as part of the landing gear in subzero temperatures now has to withstand heat levels almost twice that of boiling water at sea level. Most “normal” air is highly susceptible to Charles’ Law, but nitrogen, with its boiling point of -173 deg C, is not. That makes it ideal: the tyres are less likely to change shape/pressure switching between those two temperature extremes. Cars? No.

Blowouts in cars are a result of poor tyre quality, overinflation or overuse. Not the type of air used to inflate them... and anyway, normal air is already 78 per cent nitrogen to begin with, how much of a difference will a 22 per cent increase in purity levels make, unless you are brutally exploring the outer edges of the GTR’s performance envelope?

There is a fairly obvious prophylactic against blowouts and that is preflight checks... both for aircraft and for motor vehicles. Use proper quality tyres, inflate them to the correct pressures and try not to drive like your running gear is similar to Fred Flintstone’s.


My Subaru seems a little too thirsty


Hey Baraza,

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