Assuming the gap in 1995 and 1990 was 8% too just like in 2000, we arrive at real-world CO2 figures for 1995 of 201 g/km and for 1990 5% higher i.e. 211 g/km. This compares with a real-world 170 g/km in 2013 (127 * 1.35). This implies new cars were around 20% (1-170/211) better than they were in 1990.
The fuel efficiency of heavy goods vehicles has stagnated since 1990, according to a graph from a report of EU vehicle manufacturing industry association ACEA. No visible progress since 1990 can be discerned.
A report from the International Council for Clean Transportation (ICCT) tracks progress in fuel efficiency of new aircraft. Trends in the key graph from the report are below.
The graph shows that from 1990 to 2000 fuel efficiency of new aircraft improved by 0.7% a year per seat km, or 7% over the decade. Post-2000, no improvement was seen (0.0%). Overall progress since 1990 hence amounts to around 7%.
CE Delft report on ship efficiency 2015:
● Bulk carriers: report Figure 9: from around 5% below EEDI reference line to around 7% above between 1990 and 2013: average fuel consumption up 12%;
● Tankers: report Figure 13: from around 7% below EEDI reference line to around 2% above between 1990 and 2013: average fuel consumption up 8%;
● Container ships: report Figure 17: from around 16% below EEDI reference line to around 8% below between 1990 and 2013: average fuel consumption up 8%;
For the three ship types together, average fuel consumption per available tonne km in 2013 is around 10% higher than in 1990.