Actually, its quite challenging to properly do an old vs new offroad test for 4x4s because there are too many variables and variances across cars, terrains and performance metrics. We at IJC have had some years of experience undertaking such tests in a somewhat controlled environment and can probably say a thing or two about it....
In this case: FJ vs Patrol - my general view based on observation and experience is that any Patrol would outperform a comparable FJ at least 80% of the time. Its as reliable, has more articulation and usually more HP and Torque too.... As for the non-sensical but witty old vs new question, it would perhaps be more interesting comparing the following 4x4s:
- FJ40 vs FJ Cruiser
- JK Wrangler against the 1942 Willys
- Hilux 1984 against the Vigo Champ
- SJ Cherokee / Wagoneer (with quadratrack) against the TLC 200
In short, if you are ruling out the high speed stuff, the old cars would give the new ones a very good run for the money and produce some cheeky surprises. But in the end, even if you eliminate the secondary factors like creature comforts, ease of driving and things like the water seeping in, the new ones WILL outperform the old. Its been a competitive evolutionary process for the 4x4 world and all the time and investment in design and tech will show up in the end one way or the other....