Regular gas in place of premium?

[emperor_black]

When the last time the gas prices were high, I heard on the news that its ok to put regular gas in place of a "premium only" car only if the car's engine is normally aspirated (as opposed to super-charged or turbo charged). Is that true? What do you guys do? I have been putting regular gas for my Mercedes C240 with a normally aspirated V6 engine for the past 2 years or so and its been running just fine. But is that a disaster waiting to happen or something?

[straycat]

A car that is labled premium only you should use premium gas.I had an Acura 2.5 TL and it was labled as such, the engine is more efficient when premium gas is used.Use reg grade gas will lower your mileage.
Using premium in a car that is normally supposed to run on reg won't affect anything but your wallet.
My neighbor is a Mercedes/Jaguar mechanic and thats what he said.Premium labled cars need the extra octane.

[texasfury]

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[GryphonGuitar]

Most modern engines have adaptive knock sensors though, which will cope with regular, and change the ignition according to the gas You put in - check Your owner's manual. Even most new turbocharged cars have this - provided the turbos are not too whoo-hoooge.

However, a word of caution of course. If the manufacturer says premium only, You have realize they're drawing the line 1000 miles on the safe side, but there's still a line for a reason. I have a turbocharged car and would never put anything close to regular unleaded in it.

[DonP]

My 2007 Acura TL Type S has an 11 to 1 compression ration. You better believe it will get nothing other than premium. I get 29MPG with 286HP.

What does this cost me extra over regular? $3.84 for regular vs. $4.04 for premium. When gas is $4 a gallon, an extra 20 cents don't mean shit percentage wise.

But as was said above, I won't put premium in an engine that doesn't need it, because you are just wasting money. Hi-octane is to prevent engine damage, not to increase gas milage. However, a higher compression engine is mechanically more efficient, and because of this it gets more power out of every drop of gas it uses.

Example - you have a 1999 Saturn SL2 that runs on regular that gets 38MPG. If you rebuild the engine and can design it for higher compression (without changing anything else that would increase HP), you might get over 40MPG, but you'd have to switch to premium to keep the engine from detonating to death.

[SEEGERMANY]

The Chevron station near my house is carrying nothing but regular gas and diesel.

[CharvelRocker]

If you can use premium, it will say it's recommended. If you can't, it will say it's required. We ran into this when we were looking at a new car, and were interested in a couple Nissans, and the dealer told us you can put regular in it, but it will probably hurt the amount of power you get somewhat.

[ADR]

If you car does not ping on 87 octane,putting a higher octane 93 will not do anything except take your $$$$$$.
I own a Impreza STi. Turbo/Intercooler.My car demands 93 (boost),if I do not run 93 can cause excessive pinging which will damage the engine (crack pistons etc)
The more the octane the slower the burn.New cars that are not Turbo'ed or SC'd can run mid or Reg w/no problems.Also the higher the altitude the lower the octane required.

[Spivonious]

Somewhat related question...my car's manual "recommends' 5w20 oil. Would 10w30 hurt it or would it just need an oil change more often?

[joelayres]

It really shouldn't matter, but with the increased viscosity you may find starting a bit tougher when the weather goes below zero.

[Norton]

If you car does not ping on 87 octane,putting a higher octane 93 will not do anything except take your $$$$$$.
I own a Impreza STi. Turbo/Intercooler.My car demands 93 (boost),if I do not run 93 can cause excessive pinging which will damage the engine (crack pistons etc)
The more the octane the slower the burn.New cars that are not Turbo'ed or SC'd can run mid or Reg w/no problems.Also the higher the altitude the lower the octane required.

You have 87 and 93 in the USA?


We have 95,97 and 100 here. I wonder why.

[ADR]

You have 87 and 93 in the USA?


We have 95,97 and 100 here. I wonder why.

. . I have no idea,but love to run that in my STi.

ps: 5W-20, sounds like you have a Honda or Ford. I was told only to run that specific weight,asked the tech when I bought my 02 civic. Because of the very close tolerences do not go heavier. The thicker the oil the slower it gets to the top of the motor,the thinner oil helps at start up so parts get oil faster.
Also a thicker oil may effect gas milaege as well,I'd stay with 5W-20 per manufacturer recc. Unless you live in Arizona etc,extreme heat all year round.

[Maximum_Crunch]

If your not getting detonation i wouldn't worry about putting premium back in it.

[Spivonious]

You have 87 and 93 in the USA?


We have 95,97 and 100 here. I wonder why.

I think it's measured differently over here.

[shreddermon]

You should use whatever grade fuel that the manufacturer recommends. If it's premium, use premium.

Yes, with most late-model cars that require premium, you can get away with regular gas "in a pinch". i.e., You're on a road trip, running on E, and the gas station doesn't have premium. Yes, you can fill with regular then. But it's not recommended for standard practice everyday. Consider it an "emergency" option, if needed. And then fill her back up with premium at the next chance.

My Speed6 gets nothing but premium, as required.