diff --git a/ci-operator/step-registry/ipi/conf/aws/ipi-conf-aws-commands.sh b/ci-operator/step-registry/ipi/conf/aws/ipi-conf-aws-commands.sh
index e94bff408f874..132a748b6ab0c 100755
--- a/ci-operator/step-registry/ipi/conf/aws/ipi-conf-aws-commands.sh
+++ b/ci-operator/step-registry/ipi/conf/aws/ipi-conf-aws-commands.sh
@@ -5,58 +5,133 @@ set -o errexit
 set -o pipefail
 
 # TODO: move to image
-curl -L https://github.com/mikefarah/yq/releases/download/3.3.0/yq_linux_amd64 -o /tmp/yq && chmod +x /tmp/yq
+curl -sL https://github.com/mikefarah/yq/releases/download/3.3.0/yq_linux_amd64 -o /tmp/yq && chmod +x /tmp/yq
 
 export AWS_SHARED_CREDENTIALS_FILE="${CLUSTER_PROFILE_DIR}/.awscred"
 
+declare -g MASTER_FAMILY
+declare -g MASTER_TYPE
+
 CONFIG="${SHARED_DIR}/install-config.yaml"
+REGION="${LEASED_RESOURCE}"
 
 expiration_date=$(date -d '8 hours' --iso=minutes --utc)
+existing_zones_setting=$(/tmp/yq r "${CONFIG}" 'controlPlane.platform.aws.zones')
 
 function join_by { local IFS="$1"; shift; echo "$*"; }
 
-REGION="${LEASED_RESOURCE}"
+# Size definition (ipi-conf-aws-ref.yaml): ref.env["SIZE_VARIANT"].documentation
+function get_master_size {
+  master_size=xlarge
+  if [[ "${SIZE_VARIANT:-}" == "xlarge" ]]; then
+    master_size=8xlarge
+  elif [[ "${SIZE_VARIANT:-}" == "large" ]]; then
+    master_size=4xlarge
+  elif [[ "${SIZE_VARIANT:-}" == "compact" ]]; then
+    master_size=2xlarge
+  fi
+  echo ${master_size}
+}
+
+function set_MASTER_TYPE {
+  MASTER_TYPE="${MASTER_FAMILY}.$(get_master_size)"
+}
+
+function choose_preferred_type {
+  local type_preferred
+  local type_backup
+  local zones_cnt_pref
+  local zones_cnt_backup
+
+  type_preferred="${1}.$(get_master_size)"
+  type_backup="${2}.$(get_master_size)"
+
+  if [[ ${existing_zones_setting} == "" ]]; then
+    zones_cnt_pref=$(aws ec2 describe-instance-type-offerings \
+      --region "${REGION}" \
+      --location-type availability-zone \
+      --filters Name=instance-type,Values=\"${type_preferred}\" \
+      --query 'InstanceTypeOfferings[].Location' \
+      --output json | jq -r '. | length')
+    zones_cnt_backup=$(aws ec2 describe-instance-type-offerings \
+      --region "${REGION}" \
+      --location-type availability-zone \
+      --filters Name=instance-type,Values=\"${type_backup}\" \
+      --query 'InstanceTypeOfferings[].Location' \
+      --output json | jq -r '. | length')
+  else
+    zones_expr=$(echo "${existing_zones_setting}" |jq -r '. | join("|")')
+    zones_cnt_pref=$(aws ec2 describe-instance-type-offerings \
+      --region "${REGION}" \
+      --location-type availability-zone \
+      --filters Name=instance-type,Values=\"${type_preferred}\" \
+      --query 'InstanceTypeOfferings[].Location' \
+      --output json \
+      | jq -r ".[] |select(.? | match(\"${zones_expr}\"))" \
+      | wc -l)
+    zones_cnt_backup=$(aws ec2 describe-instance-type-offerings \
+      --region "${REGION}" \
+      --location-type availability-zone \
+      --filters Name=instance-type,Values=\"${type_backup}\" \
+      --query 'InstanceTypeOfferings[].Location' \
+      --output json \
+      | jq -r ".[] |select(.? | match(\"${zones_expr}\"))" \
+      | wc -l)
+  fi
+
+  if [[ ${zones_cnt_pref} -ge ${zones_cnt_backup} ]]; then
+    MASTER_FAMILY="${1}"
+  else
+    MASTER_FAMILY="${2}"
+  fi
+}
+
 # BootstrapInstanceType gets its value from pkg/types/aws/defaults/platform.go
 architecture="amd64"
-arch_instance_type=m5
+
+# choose the preferred instance type depending of the availability on the
+# region. If the availability is equal, the preferred will be chosen, otherwise
+# the backup will be.
+# See more in PreferredInstanceType() pkg/asset/machines/aws/instance_types.go
+instance_preferred=m6i
+instance_backup=m5
+arch_instance_type=${instance_preferred}
+
 if [[ "${CLUSTER_TYPE}" == "aws-arm64" ]]; then
   architecture="arm64"
   arch_instance_type=m6g
+  MASTER_FAMILY="${arch_instance_type}"
+else
+  choose_preferred_type "${instance_preferred}" "${instance_backup}"
+  arch_instance_type=${MASTER_FAMILY}
 fi
 
+set_MASTER_TYPE
 BOOTSTRAP_NODE_TYPE=${arch_instance_type}.large
 
 workers=3
-if [[ "${SIZE_VARIANT}" == "compact" ]]; then
+if [[ "${SIZE_VARIANT:-}" == "compact" ]]; then
   workers=0
 fi
-master_type=null
-if [[ "${SIZE_VARIANT}" == "xlarge" ]]; then
-  master_type=${arch_instance_type}.8xlarge
-elif [[ "${SIZE_VARIANT}" == "large" ]]; then
-  master_type=${arch_instance_type}.4xlarge
-elif [[ "${SIZE_VARIANT}" == "compact" ]]; then
-  master_type=${arch_instance_type}.2xlarge
-fi
 
 # Generate working availability zones from the region
 mapfile -t AVAILABILITY_ZONES < <(aws --region "${REGION}" ec2 describe-availability-zones | jq -r '.AvailabilityZones[] | select(.State == "available") | .ZoneName' | sort -u)
 # Generate availability zones with OpenShift Installer required instance types
 
-if [[ "${COMPUTE_NODE_TYPE}" == "${BOOTSTRAP_NODE_TYPE}" && "${COMPUTE_NODE_TYPE}" == "${master_type}" ]]; then ## all regions are the same 
-  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
-elif [[ "${master_type}" == null && "${COMPUTE_NODE_TYPE}" == null  ]]; then ## two null regions
-  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
-elif [[ "${master_type}" == null || "${COMPUTE_NODE_TYPE}" == null ]]; then ## one null region
-  if [[ "${BOOTSTRAP_NODE_TYPE}" == "${COMPUTE_NODE_TYPE}" || "${BOOTSTRAP_NODE_TYPE}" == "${master_type}" || "${master_type}" == "${COMPUTE_NODE_TYPE}" ]]; then ## "one null region and duplicates"
-    mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
+if [[ "${COMPUTE_NODE_TYPE}" == "${BOOTSTRAP_NODE_TYPE}" && "${COMPUTE_NODE_TYPE}" == "${MASTER_TYPE}" ]]; then ## all regions are the same 
+  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
+elif [[ "${MASTER_TYPE}" == null && "${COMPUTE_NODE_TYPE}" == null  ]]; then ## two null regions
+  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
+elif [[ "${MASTER_TYPE}" == null || "${COMPUTE_NODE_TYPE}" == null ]]; then ## one null region
+  if [[ "${BOOTSTRAP_NODE_TYPE}" == "${COMPUTE_NODE_TYPE}" || "${BOOTSTRAP_NODE_TYPE}" == "${MASTER_TYPE}" || "${MASTER_TYPE}" == "${COMPUTE_NODE_TYPE}" ]]; then ## "one null region and duplicates"
+    mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 1 ' | awk '{print $2}')
   else ## "one null region and no duplicates"
-    mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 2 ' | awk '{print $2}')
+    mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 2 ' | awk '{print $2}')
   fi 
-elif [[ "${BOOTSTRAP_NODE_TYPE}" == "${COMPUTE_NODE_TYPE}" || "${BOOTSTRAP_NODE_TYPE}" == "${master_type}" || "${master_type}" == "${COMPUTE_NODE_TYPE}" ]]; then ## duplicates regions with no null region
-  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 2 ' | awk '{print $2}')
-elif [[ "${BOOTSTRAP_NODE_TYPE}" != "${COMPUTE_NODE_TYPE}" && "${COMPUTE_NODE_TYPE}" != "${master_type}" ]]; then   # three different regions
-  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${master_type}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 3 ' | awk '{print $2}')
+elif [[ "${BOOTSTRAP_NODE_TYPE}" == "${COMPUTE_NODE_TYPE}" || "${BOOTSTRAP_NODE_TYPE}" == "${MASTER_TYPE}" || "${MASTER_TYPE}" == "${COMPUTE_NODE_TYPE}" ]]; then ## duplicates regions with no null region
+  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 2 ' | awk '{print $2}')
+elif [[ "${BOOTSTRAP_NODE_TYPE}" != "${COMPUTE_NODE_TYPE}" && "${COMPUTE_NODE_TYPE}" != "${MASTER_TYPE}" ]]; then   # three different regions
+  mapfile -t INSTANCE_ZONES < <(aws --region "${REGION}" ec2 describe-instance-type-offerings --location-type availability-zone --filters Name=instance-type,Values="${BOOTSTRAP_NODE_TYPE}","${MASTER_TYPE}","${COMPUTE_NODE_TYPE}" | jq -r '.InstanceTypeOfferings[].Location' | sort | uniq -c | grep ' 3 ' | awk '{print $2}')
 fi
 # Generate availability zones based on these 2 criterias
 mapfile -t ZONES < <(echo "${AVAILABILITY_ZONES[@]}" "${INSTANCE_ZONES[@]}" | sed 's/ /\n/g' | sort -R | uniq -d)
@@ -65,8 +140,6 @@ MAX_ZONES_COUNT="${#ZONES[@]}"
 # Save max zones count information to ${SHARED_DIR} for use in other scenarios
 echo "${MAX_ZONES_COUNT}" >> "${SHARED_DIR}/maxzonescount"
 
-existing_zones_setting=$(/tmp/yq r "${CONFIG}" 'controlPlane.platform.aws.zones')
-
 if [[ ${existing_zones_setting} == "" ]]; then
   ZONES_COUNT=${ZONES_COUNT:-2}
   ZONES=("${ZONES[@]:0:${ZONES_COUNT}}")
@@ -101,7 +174,7 @@ controlPlane:
   name: master
   platform:
     aws:
-      type: ${master_type}
+      type: ${MASTER_TYPE}
 compute:
 - architecture: ${architecture}
   name: worker