As long as you're not heavy footed the 275 is a great gas mileage tune. Lots of guys run it with no issues.
From Spartans website :
Important DashDAQ Gauge Warnings
EGRTA – Pre Turbo EGT's High Limit - 2,000 High Warning - 1,600
EOT – Engine Oil Temp High Limit - 250 High Warning - 220
ECT – Engine Coolant Temp High Limit - 240 High Warning - 215
FRP – Fuel Rail Pressure High Limit - 30,000 psi High Warning - 27,500 psi
FRT – Fuel Rail Temp High Limit - 200 High Warning - 140
TFT – Transmission Fluid Temp High Limit - 240 High Warning - 215
MGP - Manifold Gauge Pressure (Boost) High Limit - 55 psi High Warning - 48 psi
EP - Exhaust Back Pressure (absolute) - Subtract barometric pressure from the number you see on the DashDAQ for this reading! High Limit - 80 psi High Warning - 75 psi
TCSLIP(RPM) - Torque Converter Slip - This only matters when the torque converter is locked. If the converter is unlocked, the reading will be extremely high. Therefore do not set an alarm for this!! High Limit - 200 RPM High Warning - 100 RPM
Jeff Dodd - Administrator firstname.lastname@example.org
Hope this helps.