There are just very limited items that in the SAE standard which have alternate definitions. Many parameters, for example hip room, shoulder room etc., have only one definition. For leg room, only the driver seat has 2nd definition, others all have one single definition. So most of the publicly available measurements can be compared horizontally across different makes and models.
When German/Japanese brands selling vehicles in countries other than the US, they can report measurements on their own or following the local regulation. For vehicles sold in US, the measurements published for the US market should be using the SAE standard. So most of the foreign brands simply use the SAE standard internationally to avoid the hassle, except some terms such as weight and power.
So all these reviewers (from different countries, much less different continents) are just imagining things when they state that the G70's space is tighter than the competition? lol
There is no
standard that all automakers use in these measurements (BMW, for instance, is notorious for under-reporting its HP figure).
And even if there were, things don't always reflect in the real world - such as EPA mileage figures, esp. for turbo engines and BEV range.
There was a test done on a # of EVs in the UK to see what their actual range was compared to their claimed range.
The EV that did the poorest was the MB (
75% of claimed range).
The EV that did the best was the Kia (
90% of claimed range).
Why would it vary so much if the automakers are using some standard to measure range?
Rear legroom
A4 - 35.7 "
3 Series - 35.2 "
G70 -
34.8 "
C Class - 35.2 "
Rear headroom
A4 - 37.4 "
3 Series - 37.6 "
G70 -
36.9 "
C Class - 37.1 "
- Based on these measurements, the G70 has both the
least amount of legroom and headroom at the rear.
Having the lowest amount of headroom causes taller passengers to slouch, pushing their legs forward and hence, making the tighter legroom situation even worse (and that's not even taking into the account the poor footwell space).
In their comparison (w/ the 3er), Cars.com states that there's more room in the BMW (
19:07 mark).
At the 20:25 mark, they go into how the claimed 17.0 cu.ft. of trunk space in the BMW is
bunk, going into how measurements from automaker to be
unreliable and
inconsistent (which is why they do their own measurements).