What type of oil should I use?

Hello, The actual engine depends on the mileage of the vehicle, climate in which you drive, and whether or not you have made any mods. For a Celica with about 75,000, 10w30 recommended. You may want to check for yourself at http://www.valvoline.com to make sure it wouldn't recommend high-performance or high-mileage oils. Best of luck! CarGrrl

If you are asking what weight use 10w30 or even 10w40 for higher miles. If you are asking brand name, any will work if you change it regularly. I don't want you to go against the manufactures recommendation but I have been using Castrol GTX 20w50 in my Corolla for 20 years and 600,000 miles.

Thinner oil weight, like a 10w30 will give you the best m.p.g. but at the sacrifice of faster oil breakdown of viscosity and greater oil consumption, especially in cars with mileage over 75,000 on the odometer (older cars), so if you have the typical used car, then you should use a heavier weight oil (as long as you don't live in extremely cold climates)... I personally use 20w50 weight oil in all my engines, here in the warm climate of Carolina, and I usually add 70w racing oil at top off (a good product is High Tach, or Lucas Oil Stabilizer), for older used cars, especially if they're driven for long duration or in stop and go traffic often.

...and remember to change your oil often, go by the color and the look of the oil, for motor oil is designed to hold dirt and harmful metallic particles in suspension, coating the particles, in an attempt to reduce friction from wear, and as the motor oil is used in a running engine it becomes a bit dirtier each day, eventually to the point of saturation of things not good for your car (change it every 3 to 5,000 miles, anything beyond that is just taking risks that one should not take), and always change your oil filter too!

.... friction from wear caused by the dirt & metallic particles wearing away at your various oil seals, pistons & their cylinder rings (these rings keep the oil where it belongs & so when they wear out beyond spec then you will burn oil and eventually trash the engine) and valve stems & rings (as these wear you get oil blow by, oil excess being blown into the combustion chamber and out the exhaust, in other words you'll either break the bank buying & adding oil or you'll simply blow your engine!

...and don't overfill your oil level, if you do then you could cause the main engine oil seals to break, and to leak & burn even more oil (check your oil level with the dipstick when the motor is off and somewhat cool).

...the excess oil, if you overfill, will increase the oil pressure in the motor and could possibly blow out your seals, enough to cause a leak.

...of course not enough oil will result in faster oil viscosity break down, and eventually the overheating of your engine due to metal on metal friction wear, thus resulting in a trashed engine.

The nulon high performance one or the gold bottle gt one from bp. Anything for race purposes. I would be more worried about a lack of oil or poor quality oil destroying my engine than mpg!

I have celica gts with 45k on engine. What oil I should get, I mean do you guys recommend?

5W-30 is the recommended oil. Use what the manufacturer recommends. If over 75K, use 5W-30 High Mileage.