The dyno graph from Automobile states WHEEL horsepower not crank which is what cars manufacturers use.
Not necessarily.
With the ION Redline, all of Saturn's info says it is rated at 205 HP. A LOT of people actually dyno their ION Redlines in the 205-210 WHP range. So...for that, Saturn is quoting Wheel HP.
Also, this reason is why SAE changed it's standards recently. Many Japanese automakers were claiming their cars had X amount of HP, which made them seem 20-30 HP better than the direct American competitor cars. However, it was discovered that the American manufacturers were quoting Wheel HP, while the Japanese were quoting Crank HP. And no one was actually explaining that in their advertisements. So SAE changed the regulations sometime during the last year, so that all manufacturers would report their HPs as Wheel HPs.
Crank HP cannot be measured, it can only be estimated based on a measured Wheel HP. So, up till last year, the Japanese were 'artificial' boosting their HP numbers in the sales info by quoting Crank HP estimates instead of hard and fast Wheel HP measurements.
Hence my wondering if there is a different standard for Rear Wheel Drive cars than for Front Wheel Drive.
Oh, and on a similar note...GM is notorious for under-rating the HP in their engines. I know many people with ION Redlines who Dyno'd 210 WHP or more completely stock. So, it wouldn't surprise me at all if that torque curve actually does go above 260.