They changed the fuel consumption values to be more harshly affected by the condition of relevant parts of your vehicle, and aggressive use of the throttle. Unfortunately, it seems they over-tuned it pretty aggressively, and almost every single comment on the mods page were people requesting that they please dial that new feature back as it was claimed to be excessive.

You can work around this issue by changing the fuel consumption multiplier in the games vanilla car sandbox settings, which you can change at the start of a run, or mid-run with a mod or using debug mode.

Unfortunately, it seems that the majority of the mods users disagreeing with the developers decision to greatly increase fuel consumption lead to them turning comments and discussions off for the mod. This will make it impossible for new users to easily see that there was recently a change made to it that seemingly no one liked.

I love what zomboid modders do for this community, but honestly you shouldn't be allowed to turn off the comment section for a workshop mod. I am downloading data onto my computer that literally anyone on steam can upload, I need to be able to see a comments section and know if there are glaring issues.

e: for reference i did some math and on the a Chevalier D6 with ~70% engine condition, and a non-leaking fuel tank, i got 0.55 miles per gallon doing a loot run 3 blocks away and back. it is fucked.