Sacha, The antifreeze/water ratio should not cause your overheating problem. Most likely, it is caused by air trapped in the cooling system. There is a natural high point pocket above the thermostat and a brass fitting on it to allow you to bleed the air out. Check the archives for the procedure. If your coolant was low once, you probably have a leak in the system and before you drive too much, you must find and correct it. There are a large number of short hoses in the cooling system loop (and twice as many hose clamps) and at least one is probably leaking. The original maintenance schedule called for the coolant to be drained and replaced every 15,000 miles. If you don't know when it was done last, it probably should be done as soon as you are sure you have fixed the leak. After you have drained and refilled, remember to bleed the system again. Hank Breer VIN 1141