First of all, it should be clear that any amount of riba or interest is prohibited. Therefore, a low or high rate of interest is prohibited as there is no reference in the Qur’an or the Sunnah differentiating between low or high rate of interest even though the high rate of riba incurs more grievous sins.

Dr. Monzer Kahf, a prominent economist and counselor, states, Interest is the most common kind of riba, no doubt about it. It is the kind of riba that is prohibited in the Qur’an and Sunnah and it is the kind that we usually mean when we say riba (without any qualification or adjective). It is called in the fiqh literature riba ad-duyun or riba al-qurud [Arabic for: interest of debts and interest of loans respectively].

This kind of riba is defined in Shari`ah as an increment stipulated in a loan contractor in a debt rescheduling (for the time difference between giving the loan and repaying it or for delaying a debt to a further due date).
Kindly notice that there is no reference to a low or high rate. Therefore, a low rate of interest is e
qually prohibited. Of course, high rate is double evil because it is riba and it is exploitativel, too. Prophet Muhammad’s (peace and blessings be upon him) reference to “an atom of riba” is some of his Sayings.
Riba
is one of the most grave sins according to our religion; it is the sin about which Allah said that a war is declared from Him and His Messenger on those who do not quit dealing with it. The Prophet (peace and blessings be upon him) said that the wrath of Allah is on the taker, the giver, the writer, and the two witnesses. And in some other saying of the Prophet (peace and blessings be upon him) said, “They are all equal [in the sin].”

Any prohibition may have certain necessity circumstances that call for relaxation. This applies to riba and to many other prohibitions. Of course, a necessity must always be given its right weight since it is Allah, the Most Knowledgeable, Who is going to screen our truthfulness, not any one else.
I can see a quasi-necessity in buying homes in some countries like the US and Canada, but I hardly find it for buying cars because the affordable used-cars market reduced such necessities to a minimum.