Compounds and fuel compositions

A crude oil, lubricating oil or fuel oil composition exhibiting improved cold flow properties consisting essentially of said oil and a flow improvement additive in an amount of 10 to 2,000 ppm of the oil, the additive being a chemical compound having a cyclic ring system, the compound carrying at least two substituents of the general formula (I) below on the ring system

• --A--NR.sup.1 R.sup.2 (I)
• where A is an aliphatic hydrocarbylene group that is optionally interrupted by one or more hetero atoms and is straight chain or branched, and R.sup.1 and R.sup.2 are the same or different and each is independently a hydrocarbyl group containing 9 to 40 carbon atoms optionally interrupted by one or more hetero atoms, the substituents being the same or different and the compound optionally being in the form of a salt thereof, subject to the provisos that the ring system is not an alkyl-substituted phenol, that when it is dimethylbenzene R.sup.1 and R.sup.2 contain at least 16 carbon atoms, and that when R.sup.1 and R.sup.2 of one substituent are both alkyl, R.sup.1 and R.sup.2 of the or each remaining substituent are not both interrupted and substituted alkyl or interrupted and substituted aralkyl groups.