Ask the Mechanic

Thursday April 22 2021
By Paul Kaganzi

Can I change to bigger tyres?

Hello Paul, can I replace the 185/70 R14 on my ST210 Toyota Corona Premio with the wider 195/65 R15? Are there any advantages of larger wheels and tyres than those recommended by the factory? 


Hello Mukundane, Toyota recommends two wheel (tyre) sizes for your Corona Premio ST210; the smaller 175/70 R14 and the bigger 185/65 R14. The bigger wheel size you suggest 195/65 R15 is recommended for the differently designed post 2002 Toyota Premio.

Manufacturer recommended wheel sizes are selected after rigorous testing of the car profile and suspension design. This takes into consideration details such as the wheel arch depth. Driving on bigger or smaller wheel sizes outside the recommended wheel size range will compromise your car handling characteristics as well as cause damage in extreme cases where the wheels are too big to fit next to the suspension or wheel arch.

That said, professional wheel centres can help you calculate a wheel aspect ratio that can come close to the manufacturer recommended tyre size alternatives. Briefly, there are a few advantages of upgrading to larger wheel. Your car handling will be better due to improved road grip and traction courtesy of the wider rubber on road surface. Your car will also experience improved cornering as well as braking and aesthetically, wider tyres look better.


The downside of bigger size wheels is that they are more expensive to acquire, wear out faster and tend to reduce fuel economy due to increased rolling resistance. Bigger tyres make your steering harder and acceleration slower.

A cost benefit analysis of the pros and cons should be considered and an upgrade within the manufacturer recommended range of sizes.


How can I maintain my new TVS 125 Motorcycle?

Hello Paul, I have just bought a new TVS HLX 125 to ease transportation and I would like to maintain it in perfect condition. Please give tips on how to achieve this.


Hello Quraish, the TVS HLX 125 is a reputable workhorse with a four-stroke naturally cooled engine. Spare parts are easily available through a network of sub-dealers probably at the nearest boda boda stage. Their undoing seems to be the choice of engine oil and source of fuel.

Go for advance motorcycle lubricants to service the clutch as well as keep the engine clean and free of sludge and dirty. Advance lubricant also services the bike clutch increasing fuel economy and reliability. Also, use fuel that prevents dirt buildup in the bike fuel system.

My car is noisy during acceleration

Hello Paul, I have a Nissan Note E11 which makes a disturbing sound when accelerating from a low gear. However, the sound disappears as I move to higher gear. What could be the problem and is there any specific mechanic you can refer me to?


Hello Zedekiah, the Nissan Note has a CVT gearbox. Have you serviced the CVT fluid? You may need to get the special CVT gearbox fluid from the Nissan dealer and have it serviced. The unusual sound as you accelerate and shift upwards could be a result of a struggling CVT transmission.

When you go to the garage, have the drive shafts inspected to rule out a damaged CV joint.

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