“Not exactly: diesels would still work.”
One of the things that we’ve done to erstwhile reliable diesels is saddle them with all kinds of electronic controls in hopes of making them “cleaner”. These things make modern diesel engines susceptible to EMP, unfortunately.
If you have an engine, you can transport, or provide electricity, until the fuel runs out.
And the fuel could be mechanically siphoned out of the non-functioning newer diesels and stranded cars.
Not much, but better than nothing: but the problem is one of prioritization, and whether local politicians will commandeer all such resources for their own personal use.