Firefighters were at the scene at around 5am on Friday, July 17, to tackle the fire.
The incident is now being investigated by South Wales Police and is thought to be arson.
Another car was found abandoned with a broken window and smashed into a lamp post nearby in Constitution Hill, Mount Pleasant. The lamp post and metal railings were damaged in the collision.
The incidents come less than a week after at least seven cars had windscreens and windows smashed on Sunday night in the same area.
There were also further attacks over the weekend in various parts of Swansea.
Local resident, Zoe Morgan, 44, came across the torched cars at around 6am while she was on a dog walk.
She said her own car had been stolen about 18 months ago and that residents were becoming increasingly frustrated.
“I was just walking past this morning and saw a car that looked like it had been torched. Two cars either side of it were also damaged as well as the pavement,” she said.
“I assumed it had happened overnight because I didn’t notice anything yesterday and there was no heat coming from the car.
“The area is so lovely with a good community feel, it’s just so frustrating that this keeps happening. I called the police on Monday because I came across damaged cars.
“People are having to fork out extra costs on security measures because it happens so often.”
Uplands councillors Peter May and Irene Mann visited the scene of the burnt out car today (Friday, July 17).
Mr May said they were both liaising with South Wales Police to try to put a stop to the issue.
He said: “I’ve been on site today with Councillor Irene Mann. At the moment we are liaising with the police because this cannot go on. We are asking the police to try and get patrols doubled.
“The fact is people rely on their cars to go to work in the morning, or if they have mobility issues to get out and about.
“People are feeling very vulnerable. This is something that people don’t expect to happen to them once, let alone twice in one week.
“No doubt the police are taking it seriously, but we are seeing if they can double patrols to either prevent this from happening or to catch anyone who is doing it.
“We are also looking at the installation of cameras from the community budget.”
CCTV footage shows thieves break into a car in Swansea:
A spokeswoman for South Wales Police said investigations were ongoing and officers had increased patrols in the area in uniform and plain clothes.
“We were made aware of a car being on fire in Penlan Crescent at about 5.10am this morning,” she said.
“The cause of the fire is thought to be suspicious and enquiries are ongoing.
“Anyone with information should contact 101 quoting occurrence 2000253822.”
She said they also received a report of an abandoned vehicle in Constitution Hill this morning at about 7.10am.
“The owner has been located and the vehicle has been recovered.
“We have increased both uniform and plain clothes patrols in these areas. We would urge for people to be vigilant and report anyone acting suspiciously to us.”