diff --git a/README.md b/README.md
index 79328b3a39a52503e47a7a4ed55cb370a5060e44..46fcbc702283736cf65a59b9f2564cc716976df3 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,9 @@ Options:
 
 -   (optional) `rpc_url` Node RPC url e.g. http://127.0.0.1:8545
 -   (optional) `chain_id` Chain id e.g. 636363
+-   (optional) `desired_vdf_duration` Desired VDF duration = mining duration e.g. 60secs
+
+Example: `cargo run mine http://127.0.0.1:8545' 636363 60`
 
 ## Env vars
 
diff --git a/src/main.rs b/src/main.rs
index 4a7478d3add1ef14dc6bef2d268841f516cc46df..ccfe39dad5862cce133bd5b815a0317a9e273526 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -86,6 +86,8 @@ struct MineParams {
     rpc_url: Option<String>,
     // Chain ID
     chain_id: Option<u64>,
+    /// Desired VDF mean duration in seconds
+    desired_vdf_duration: Option<u64>,
 }
 
 async fn init() -> (u64, String) {
@@ -218,8 +220,6 @@ async fn main() -> Result<(), anyhow::Error> {
             if params.chain_id.clone().is_some() {
                 chain_id = params.chain_id.unwrap();
             }
-            // println!("Processing {:?}", params.file);
-            // csv::Reader::from_path(path)
             let records = read_csv(csv::Reader::from_path(params.file.clone())?);
             if let Err(err) = records {
                 error!("error running example: {}", err);
@@ -445,13 +445,26 @@ async fn main() -> Result<(), anyhow::Error> {
             let miner_addr = wallet.address();
             info!("Mining with 0x{:02x} ...", miner_addr);
 
-            let behavior = get_miner_behavior(wallet, chain_id, miner_addr);
-            // SEND IT
             let provider = Provider::<Http>::try_from(rpc_url.clone()).unwrap();
+            let latest_block = provider.get_block(BlockNumber::Latest).await;
+            let network_difficulty = Some(
+                ethnum::U256::from_str(&latest_block.unwrap().unwrap().difficulty.to_string())
+                    .unwrap(),
+            );
+
+            let behavior = get_miner_behavior(
+                wallet,
+                chain_id,
+                miner_addr,
+                network_difficulty,
+                params.desired_vdf_duration,
+            );
+
             debug!(
                 "Miner behavior: {:?}",
                 serde_json::to_string(&behavior.clone())
             );
+            // SEND IT
             let block = provider
                 .request::<[Behavior; 1], Block>("emc_mine", [behavior])
                 .await
diff --git a/src/utils/miner.rs b/src/utils/miner.rs
index 48d6eaa5c95ad06551b18164496fcf167f728759..4afe05246f9c91bc27f7a58df4e2dd93844dbc29 100644
--- a/src/utils/miner.rs
+++ b/src/utils/miner.rs
@@ -13,17 +13,40 @@ use ethers::{
 use ethnum::U256;
 
 /// Get a RPC Behavior for miner with default values, ready to send.
-pub fn get_miner_behavior(wallet: LocalWallet, chain_id: u64, to: Address) -> Behavior {
+pub fn get_miner_behavior(
+    wallet: LocalWallet,
+    chain_id: u64,
+    to: Address,
+    network_difficulty: Option<U256>,
+    desired_vdf_duration: Option<u64>,
+) -> Behavior {
     let now = SystemTime::now()
         .duration_since(SystemTime::UNIX_EPOCH)
         .unwrap()
         .as_secs();
 
+    // const VDF_DIFFICULTY_FOR_10_MIN: u64 = 72;
+    // Mean VDF difficulty per sec = 72/600 on current machine (Macbook M1) and a hash maxed to 1 day.
+    // for a network difficulty of 1000000
+    const MEAN_VDF_DIFFICULTY_PER_SEC: u64 = 12;
+
+    let quantity = match network_difficulty {
+        Some(net_dif) => match desired_vdf_duration {
+            Some(vdf_dur) => net_dif
+                .saturating_mul(U256::from(MEAN_VDF_DIFFICULTY_PER_SEC * vdf_dur))
+                .saturating_div(U256::from(1000000_u128)),
+            _ => net_dif
+                .saturating_mul(U256::from(MEAN_VDF_DIFFICULTY_PER_SEC * 60))
+                .saturating_div(U256::from(1000000_u128)),
+        },
+        //  default 1 min
+        _ => U256::from(MEAN_VDF_DIFFICULTY_PER_SEC * 60),
+    };
     let behavior_msg = BehaviorMessage{
          chain_id: U64::from(chain_id),
          to:Some(to),
          timestamp: U64::from(now),
-         quantity: U256::from(210000_u64),
+         quantity,
          input: Bytes::from("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") };
 
     // let behavior = wallet.
diff --git a/src/utils/mobility_data.rs b/src/utils/mobility_data.rs
index 6334d0dbe0273d3118ec4feeadd2685fc894f842..051c0b5c6226fb31afa36e7c37a1e48739117bbd 100644
--- a/src/utils/mobility_data.rs
+++ b/src/utils/mobility_data.rs
@@ -125,15 +125,20 @@ pub fn compute_stretched_relative_start_time(
 }
 
 /// Provide differents fake quantities depending on mobility e.g. BIKE that will be use for rewards calculation
+/// Coefficients per km from https://nosgestesclimat.fr/actions/plus/transport/voiture-5km
 pub fn quantify_mobility(service: String) -> U256 {
+    let base_quantity = U256::from(1000000 * 12); // default network difficulty * mean vdf difficulty per sec
+
+    // U256::from(1_000_000_000_000_000_000_000_000_000_u128);
     if service == "BIKE_SHARING" {
-        U256::from(1000000000000000000_u128)
+        // 0.129/0.0001 = 1290
+        base_quantity.saturating_mul(U256::from(1290_u128))
     } else if service == "BIKE_RENTAL" {
-        U256::from(500000000000000000_u128)
+        base_quantity.saturating_mul(U256::from(1290_u128))
     } else if service == "PUBLIC_TRANSPORT" {
-        U256::from(10000000000000000_u128)
+        base_quantity.saturating_mul(U256::from(1_u128))
     } else {
-        U256::from(1)
+        base_quantity
     }
 }
 
@@ -301,6 +306,6 @@ id,user_id,network,service,label,created_at,validation_datetime,from_coord,from_
         // ACT
         let result = quantify_mobility(String::from("BIKE_SHARING"));
         // ASSERT
-        assert_eq!(U256::from(1000000000000000000_u128), result);
+        assert_eq!(U256::from(15480000000_u128), result);
     }
 }