On the open road, a 5-speed manual 3.3 gets 5 mpg more than the auto 4.1, always. Around town, the 3.3 has to be worked harder. Wheels 1982 quoted 27 mpg average, while the Fairmont Ghia XE 4.1 auto gave 22 mpg best. When thrashed or towing the 3.3 has to have the boot dug into her, and it makes them thirsty. Top Speed 177 km/h, and standing start of 17.9 sec quarter as a 3.3 5-speed, 180 km/h with 18 secs ET as a 4.1 Ghia auto.
3-speed 3.3 manuals are over geared.
If it is a NSW spec 3.3, it will be thirstier than a 6 states 3.3. All NSW cars got more emission gear.
If its an auto, a 3.3 will have little or no benifit over an auto 4.1.
Some 4.1's without A/c run 2.54 or 2.77:1 diffs, while the 4speed, 3speed 3.3 runs 2.92.
Lots of utlitiy companies ran 3.3 utes and pannos, and they ran 3.23:1 diffs too. A ute without a tonneau cover looses 20 km/h off the top speed, and a pano 15 km/h.
154 Km/h for an XD Sundowner (Modern Motor), 143 km/h for an XF 4.1 4-speed ute with no tray cover (Wheels 1987).
I've found 3.3 5-speeds to be really well matched, and very economical. 5speeds run a 3.23:1 diff, and a nice overdriven 5 th.
An XF 3.3 doesn't run low tension rings. The 4.1 XF's do. That makes a difference in favour of the later 4.1's
