Former Top Gear host Jeremy Clarkson once said you cannot be a true petrolhead until you have owned an Alfa Romeo.

Mr Oh Kim Leong must have petrol in his veins then - for he drives two Alfa Romeos - a 1976 GT Junior 1600 and a 156 GTA Selespeed.

The 50-year-old bachelor, who is an embedded software developer with Hewlett Packard, also has six collectible motorcycles. These include a 2006 Ducati Paul Smart 1000 (one of 2,000 produced), a Ducati 996SPS (one of 1,780 produced) and a 1996 Kawasaki Ninja ZX-7RR (one of 500).

The metallic grey 156 GTA was first registered in July 2006, but was in the showroom for two to three years before a dentist bought it.

"He sold it to me in 2012 with a mileage of about 150,000km," Mr Oh says. "Today, it is about 190,000km."

At the heart of the 156 GTA is a 3.2-litre sonorous V6 engine. Mr Oh would have preferred a manual shift model instead of the automated manual Selespeed, but there was none available.

"As far as I know, there are three GTAs in Singapore - two 156 and one 147. They are all Selespeed," he says.

As soon as he bought it, he drove it to Penang, even though he feared something might break down. Thankfully, nothing happened.

When he got back to Singapore, he had all the coolant rubber hoses changed to longer lasting silicone ones as part of preventive maintenance.

"There was not a single piece of rubber left," he says.

He also had the coolant replaced with Evans Waterless Coolant, which is 100 per cent chemical. It involved blowing out all the old coolant and drying out the cooling system completely. The new coolant must not be mixed with water, he says.

"The boiling point is 150 deg C," he notes. "I have been stuck in a Causeway jam for over two hours and it did not overheat. You can open the coolant tank cap when the engine is hot. It merely pops and nothing gushes out."

He says he has never topped up the coolant because there was no loss.

Another conversion he did was to replace the limited-slip differential (LSD) for the front-driven wheels. The LSD splits power evenly between the left and right wheels, which improves handling.

"It is the most important modification which all GTAs need. The car will understeer badly with the stock differential, which is also weak and will break if driven hard," he declares.

He also had a set of coilover suspension fitted. And the wheels were replaced with those from an Alfa Romeo GT 3.2 V6.

"This is as far as I would go with my modifications," he says.

After four years of ownership, the car's certificate of entitlement was due and he forked out $46,000 in May 2016 to extend its life by 10 years.

He has driven the GTA to Sepang for a track day and it performed "flawlessly". Other than the track experience, he takes the Italian out about once or twice a week - more frequently than his other Alfa, which he drives once a month.

He does not commute to work on any of his motorbikes because he walks. He lives in Depot Road, which is within walking distance of his office in Depot Close.

Mr Oh says his mother does not know how many cars and motorbikes he owns and he hopes she does not find out through this article.