I have a 2010 with 200K miles that has been getting about 8 mpg less for over a year. No change in tire which are LOT. It also sometimes has a rough start in the winter. I changed the plugs last at 140K. Besides the plugs what else should I do to tune up the car? Do the spark plug wires need to be replaced after so long? SM-G920V ?
200k? Rough start in the morning? Save up- plan on a new HV Battery or Head Gasket soon. If the plugs were replaced at 140K using the correct ones, the service life should be 120K.
Egr circuit. I’d look there as low mpg could be due to clogging of the system . Good luck and keep us posted .
Cycle the emergency brake to make sure it’s not sticking, grease the brake caliper pins, clean the interior air filter, check the obd2 for codes like a cylinder misfiring, trickle charge the 12v to make sure it’s fully charged, run 40 lbs in the tires, start sourcing a factory fresh traction battery.
All of the recommended maintenance can be found in our YouTube channel. I would do all of them if you haven’t done them. Fluids, cleaning, lubing etc etc.
