| Date | Race | Track | Miles | Type | Winner |
| 3/15/98 | Marlboro
Grand Prix of Miami Presented by Toyota | Homestead | 225.3 | PO | Michael Andretti |
| 3/28/98 | Budweiser
500K | Motegi | 311.349 | PO | Adrián
Fernández |
| 4/5/98 | Toyota
Grand Prix of Long Beach | Long Beach | 165.27 | SC | Alex Zanardi |
| 4/27/98 | Bosch
Spark Plug Grand Prix Presented by Toyota | Nazareth | 212.85 | PO | Jimmy Vasser |
| 5/10/98 | Rio
400K | Rio de Janeiro | 247.912 | PO | Greg Moore |
| 5/23/98 | Motorola
300 | Gateway | 299.72 | PO | Alex Zanardi |
| 5/31/98 | Miller
200 | Milwaukee | 206.4 | PO | Jimmy Vasser |
| 6/7/98 | ITT
Automotive Grand Prix of Detroit | Detroit | 168.912 | SC | Alex Zanardi |
| 6/21/98 | Budweiser/G.
I. Joe's 200 Presented by Texaco/Havoline | Portland | 192.766 | RC | Alex Zanardi |
| 7/12/98 | Medic
Drug Grand Prix of Cleveland Presented by Firstar Bank | Cleveland | 210.6 | RC | Alex Zanardi |
| 7/19/98 | Molson
Indy Toronto | Toronto | 163.495 | SC | Alex Zanardi |
| 7/26/98 | U.
S. 500 Presented by Toyota | MIS | 500 | PO | Greg Moore |
| 8/9/98 | Miller
Lite 200 | Mid-Ohio | 187.414 | RC | Adrián
Fernández |
| 8/16/98 | Texaco/Havoline
200 | Elkhart Lake | 202.4 | RC | Dario Franchitti |
| 9/6/98 | Molson
Indy Vancouver | Vancouver | 154.972 | SC | Dario Franchitti |
| 9/13/98 | Honda
Grand Prix of Monterey Featuring the Texaco/Havoline 300K | Laguna Seca | 185.754 | RC | Bryan Herta |
| 10/4/98 | Texaco
Grand Prix of Houston | Houston | 106.89 | SC | Dario Franchitti |
| 10/18/98 | Honda
Indy Carnival Australia | Surfers Paradise | 173.29 | SC | Alex Zanardi |
| 11/1/98 | The
500 Presented by Toyota | Fontana | 507.25 | PO | Jimmy Vasser |
