Vauxhall Astra vs Saturn Astra




Can anyone answer this question.

Saturn has brought out the Astra, based on the European Vauxhall/Opel Astra. They are as far as I can tell the same car.

Vauxhall Astra- Engine Capacity 1796 cc, Cylinders 4, Valves 16v, Power 140@6300 ps/rpm, Torque 129@3800 lb/ft

and can get 44mpg

2008 Saturn Astra 3-Door XR

Engine: 1.8-liter, four-cylinder, 138 hp.

Torque: 125 pound-feet at 3,800 rpm

and only gets 32mpg


So why does the American version get such terrible fuel economy.


the engines seem slightly different, perhaps the US one is detuned for polution control.

More importantly, MPG Measurement methods are almost certainly different. In the US, the government mandates a very specific method. I don’t know what the europeans use, but I doubt it is the same.


The British have come up with a very ingenious way to increase their MPG’s: the imperial gallon!


aha! unless it’s metric, km/liter.

from my calculator:
44 km/l = 144 MPG
44 mi/ImpGal = 37 MPG

If it helps, these are the pages I got the data from.
I had not considered the difference in the gallon. US gallon = 3.8L, Imperial = 4.5L, good point


Last I was there, Europe uses liters not imperial gallons. Canada used imperial gallons and liters.

I would doubt the numbers. I rented a Vauxhaul and while an OK car, I was stopping for petro all the time. The thing would be running at about 3000 rpm on the expressway at 80-85 KPH, and that was in 4th gear. Maybe they added a 5 speed transmission or something.


Beyond the difference in gallon unit you also have to consider the US EPA fuel economy testing vs the British or EU based fuel economy testing is vastly different.

I notice even by magazines like Consumer Reports(CR) or Car & Driver don’t really match the EPA often(even revised figures). For example everyone’s golden child ‘Honda Accord’ gets 21MPG(below EPA) in CR in their 150 city/highway loop that is essentially same test across cars. Somehow the the terrible to many fuel economy Subaru Legacy manages 23MPG in the same CR test(>EPA).

Its hard to correlate different tests.


Continental Europe, yes, but the UK is actually if anything less metric than we are. They rate cars in miles per Imperial Gallon, although they do sell petrol by the liter. In most of Europe, they present it as Liters per 100 Kilometers, with less being better.