fuel for a 1990 ford thunderbird sc supercharged?

Question

what kind of fuel do i have to use for my 1990 ford thunder supercharged ddo i have to use 91 or can i use cheaper gas

Answer 1

Use 91 or better octane fuel because ur vehicle is supercharged and u don't want to run the risk of premature combustion from the compression and added pressure from the supercharger.

Answer 2

1990 Ford Thunderbird Sc

Answer 3

Mid-grade at the very minimum. Premium preferred.

EDIT: While cars that do NOT need premium fuel would waste any premium fuel that was fed to it, the converse statement is not true at all. Cars that says it NEED premium gas will need premium gas to run properly.

Any engine with forced induction (turbo charger or supercharger) will need premium fuel, as it is feeding MORE THAN NORMAL amount of air into the cylinder, and more fuel is added to balance combustion. Due to fast pressure build-up of modern superchargers and turbochargers, the pressure can build up fast enough to cause knocking, i.e. ignition by pressure alone.

Yes, there are knock sensors in your engine, that is supposed to retard the ignition timing to compensate for the lousy gas you put in. HOWEVER, the knock sensor may not work fast enough if you punch the gas pedal, expecting almost the same performance. In city level ground driving, you probably won't notice, but if you're fully loading, climbing a hill, or towing, you will sense the engine knocking, and prolonged knocking will DESTROY an engine.

Not to mention the lower level fuel will hurt power AND mileage.

Consider that in a 20-gal tank car, the difference of 20 cents per gallon is only 4 dollars per fill up. That's what? One Starbucks venti latte? It's NOT worth the trouble to skimp this way.

Answer 4

Ture it is not a high compression engine as mentioned below. It is actually a low compression engine. But, under boost conditions, It is like a high compression engine because you are force feeding air into the cylinders. The computer tuning is designed for 91 octane. You can run a lower grade, but the knock sensor will pull alot of timing out and you will lose power. it's worth the $.20 a gal to me to run the 91 octane. It should say on the gas gauge "premiun fuel only"

Answer 5

9 years auto repair tech<<<< Forget what these other people have told you. It's B.S octane does not mean more or less horse power. Octane only becomes and issue when ignition timing is advanced high. Your Ford was designed for 89 octane and that's what you want. To find out if it's good enough buy a couple gallons of 87 grade when you are very low on fuel. Drive the car for about 15 minutes to warm it up well. Get into high gear or over drive around 40 + MPH. Press firmly on accelerator but not hard enough it will down shift. Listen for a ping sound coming from the exhaust. If it pings try 2 gal of 89 and repeat. If you have a lot of carbon build up in your engine you may experience spark knock or ping no matter what grade you use. De carbonize engine before you start using a lower grade of fuel. If you vehicle was set up to run on 87 octane and you use 89 or 93 it's wasting your money. It will not produce more power from a higher octane rating unless your ignition is adjusted.

Don't let the premature combustion thing scare you. Again that only applies to highly advanced ignition timing. The supercharger has no effect on ignition. Premature combustion comes from a very lean mixture with high temperatures and high timing advance. Unless you have altered the engines computer in a way that it makes a lean mixture this will not happen.

http://lessgov2007.blogspot.com/index.html

Answer 6

1990 Thunderbird Sc

Answer 7

It says on the dash "Premium Fuel Only" thats 91 or better +++

also don't forget to keep fresh antifreeze in the radiator, those aluminum heads will eat out if you don't

owned 2 SuperCoupes

I just sold my 90 because it took premium fuel

My Mustang SVO turbo can take regular or premuim

Answer 8

you can use a cheper gas it doesnt really matter....unless the manual tells you otherwize because most cars are made to run on the cheaper gas...

Answer 9

high compression engine equal hi octane gas.

Answer 10

you can use cheaper gas but, cheaper gas means lower octane rating which means not quite as much horsepower.