Gemini 3.5 Flash vs Grok 4.5 for workflow automation

The verdict

Grok 4.5 wins, 8679

Same 12 workflow automation tasks, marked blind by three rival labs. Grok 4.5 took 6 tasks, Gemini 3.5 Flash took 0, 6 tied. Tested 18 Aug 2026.

Where they differed most

The task — The MOT reminder nobody sends

A three-bay garage in Wakefield describes its process: 'Denise goes through the diary at the start of the month and looks for anyone whose MOT is due, well, she looks at last year's card index and the DMS, and rings them, or texts if they said they prefer text, except we lose the ones who moved, and if they book she writes it in the diary and puts a sticker on the card. If they do not answer she tries again, sometimes. About a third of them go to Kwik Fit because we never got round to it.' Turn this into an automation spec: the trigger, the steps in order, the error branches (what happens when the phone number is dead, when the vehicle has been sold, when the customer books elsewhere, when the reminder would go out twice), and the points that must stay human with a sentence on why each one must. Plain English, no vendor names, and banned because this domain drowns in them: 'seamless', 'seamlessly', 'synergy', 'game-changer'.

### 1. The Trigger
On the first day of every calendar month, the system automatically scans the Dealer Management System (DMS) database to identify all customers whose vehicles have an MOT expiry date falling within the next 30 days.

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### 2. The Steps in Order

1. **Compile the Monthly Cohort:** The system generates a list of all vehicles due for an MOT in the upcoming month.
2. **Filter and De-duplicate:** The system cross-references this list with the live workshop diary. Any customer who has already booked an appointment for the upcomin…
**Automation spec: Monthly MOT due reminders**

**Trigger**  
First working day of each month (or a fixed calendar date you choose). The system pulls every vehicle whose MOT expiry falls in the current month from the digital records (the old card-index data plus the live workshop system).

**Steps in order**  
1. Build the due list: match registration, customer name, last MOT date, contact number, and preferred contact method (voice call or text).  
2. Suppress any vehicle already booked in the diary for an MOT this month, or already marked “so…

Task by task

TaskGemini 3.5 FlashGrok 4.5
The MOT reminder nobody sends58
The spec, as JSON88
Where the human stays88
The unhappy paths are the job88
Do not automate this910
It fired twice88
The spreadsheet that runs the business89
The alert that wakes someone up89
How long it really takes99
No API, no chance?89
Rules, not guesses88
Refuse the scraper89

Full receipts: Gemini 3.5 Flash, Grok 4.5 · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5

Questions people ask

Which is better for workflow automation: Gemini 3.5 Flash or Grok 4.5?

Grok 4.5 — it scored 86/100 against 79/100 on our 12-task workflow automation suite, winning 6 tasks to 0 with 6 tied. Every answer was marked blind by three judges from three rival AI labs.

How was this tested?

Both models answered the identical published workflow automation tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.

More workflow automation head-to-heads: GPT-5.6 Sol vs Grok 4.5 · Gemini 3.5 Flash vs GPT-5.6 Sol · Claude Sonnet 5 vs Grok 4.5 · Claude Sonnet 5 vs Gemini 3.5 Flash · GPT-5.5 vs Grok 4.5 · Gemini 3.5 Flash vs GPT-5.5

Full ranking: Best AI for workflow automation · model pages: Gemini 3.5 Flash, Grok 4.5