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Q LAST year, when my Holden Adventra needed new tyres, my tyre dealer suggested fitting Bridgestone Potenza 235/45 R17 tyres instead of the original 225/55 R17 Bridgestone Turanzas. The Potenzas were $30 a tyre cheaper and I was told that this was a common change, so I went ahead. But after reading about the possibility of making a car unroadworthy when such a change is made, I would like your opinion on whether the change affected my vehicle’s roadworthiness.
Graham Otte, Hoppers Crossing Swapping the 225/55 R17 tyres for 235/45 R17 is possible if you use an ‘‘extra load’’-rated tyre to get the equivalent load rating of the original tyres. But the 235/45 R17 tyres are 18mm smaller in diameter and fall outside the legal maximum of 15mm difference in size allowed. Technically, your car is unroadworthy. As a rule, going to a smaller tyre as you have done is not recommended.
Q I AM having trouble starting my 1989 Toyota Camry SV21. It won’t turn over for about two minutes and when it does finally turn over it cuts out when I put my foot on the pedal. I have had it serviced and fitted new spark plugs, new battery and a used cold-start part. Once it’s warmed up it goes really well. Can you help?
Baris Sahin, email When you turn the key you should be able to hear the starter solenoid kick in to engage the starter. If it doesn’t, it could be a problem with the solenoid. If you can hear it engaging the starter it could be the battery. Even though you say you have fitted a new one, check its condition and make sure it is one with sufficient cold-cranking capacity for your car. When it does fire, don’t put your foot on the throttle immediately. The SV21 has fuel injection and doing that will confuse the ECU. Just let it run for a moment before trying to drive away.
Q MY DEALER’S service centre recommended I get the ‘‘injector service’’ done with the 15,000km service on my Ford Focus. I bought it new last year and it has done only 11,000km, and to date I’ve had no problems with it. I didn’t agree to the service because I thought there was no need for it to be done so early in the car’s life. Can you advise when this type of service would be required?
Dennis, email There really isn’t any need to do an injector service; the dealer is just selling you up to something you don’t need. You probably will never need to have an injector service, but if the car starts to run roughly later on you could then have the system cleaned. I wouldn’t expect that to happen before at least 80,000km, if ever.
Q IS THERE an LPG kit for a petrol 2007 Nissan Pathfinder?
Mark Gretgrix, email There have been issues with the catalytic converters overheating, breaking up and being ingested into the engine with Pathfinders running on LPG and installers generally don’t recommend it. The guys at the Australian LPG Warehouse tell us they recently fitted a Pathfinder with one of their JTG liquid-injection systems. They say the combustion temperature with their system is the same as it would be on petrol, alleviating the problem with the cat converters.
Short-changed: a change of tyre was for the worse on Adventra.