Thread:RR3'tyoloo/@comment-25956839-20161106141538/@comment-28328990-20161106172311

To get past 8.3, he upgraded to 1321111 spending 90 gold.

For 8.4, he found Magnus incredibly fast and tried upgrading to 6321111 and despite getting near to him, he could not win the race. This might be the gold trap and decided to skip for 70 gold.

Conclusion:

For experienced drivers, 2 ways to win the car.

1. Upgrade to 1321111 and skip 8.4. Overall, net loss of 20 gold.

2. Skip 8.3 and 8.4 for 140 gold. Even cost overall.

For new drivers, they are answered by the Fandom User directly below Sirebel's.

Basically, he didn't try to pass 8.4 by upgrading and just skip it entirely.