Article states non-premium fuel voids warranty

[rfernatt]

CNN/AOL Autos article on fuel requirements uses smart as an example:

Can you dodge premium gas? - CNN.com

"The little two-passenger smart fortwo is the most fuel-efficient car (not counting hybrids) in the U.S. market, with EPA fuel economy ratings of 33 mpg city, 41 highway. For high-mileage frugality, it appears to beat the five-passenger Toyota Yaris and its 29/35-mpg ratings by a long shot.

But wait! Premium fuel -- which cost about 12 percent more than regular at U.S. pumps last month -- is required for the fortwo. Suddenly the gap closes and the Smart no longer looks like as strong of a fuel-budget buster. And with the requirement, they mean it: smart says you'll lose your warranty coverage if you don't ante up."


Anyone actually heard this from a dealer or smartUSA? I run premium, so it doesn't matter to me, but this is the first time I've seen the warranty issue stated. I'm pretty sure they mean if you run the car on regular over a prolonged period, not filling up here and there if premium wasn't available.

[Godfather]

PT Barnum was right...........

[fpage77]

You know what's weird is I've only seen 93 octane around and that's what I have been putting in my car. I wonder if putting in higher octane than 91 will cause problems with car if it was set to run on 91 octane.


.... not sure if I am answering my own question but .....

The actual heat energy in gasoline is typically the same whether it's regular or premium, but the higher octane rating means it can burn in a more controlled fashion -- useful only if the engine can take advantage of it. "Higher-octane gasoline doesn't make any more power, but it enables higher compression, or enables the turbochargers to produce more boost," says Nielsen.

[Godfather]

This car "needs" premium like California needs more taxes..............

[jwight]

Somewhere on here is the discussion by Dave Schembri from last year saying occasional use (or words to that effect) of lower than 91 octane gas was OK. Nothing about warranty.

Found it: Schembri says Regular OK

[Old smart]

A few things can happen with a high compression engine running on lower than specified octane fuel.
(a) If the ECU cannot retard the ignition timing enough under all loads to accommodate the low octane fuel and detonation occurs, the smart’s delicate, expensive “slipper” pistons could be damaged.
(b) Retardation of ignition timing results in increased exhaust gas temperature, thus:
-(b1) The temperature of the exhaust port side of the aluminum head is higher than engineered compared to the cool induction side, putting stress across the casting (think head warping).
-(b2) Grossly retarded ignition can expel un-burned fuel into the exhaust system, thence to the catalytic converter (which in a smart is only a few inches away, not like a few feet away in a larger car), and which can destroy the effectiveness of the cat.

Any of the above could be a cause for warranty denial.

[Macaw]

Now when gas was $4 a gallon last year and is now $2 gallon how come the difference in price of 87, 89 and 93 octane was exactly the same 10-cents a grade ! And that makes the percentage difference even less when it's $4 a gallon! so the higher the gas price the better off you are in a smart...lol

[SuperGeek]

Originally Posted by Old smart

A few things can happen with a high compression engine running on lower than specified octane fuel.
(a) If the ECU cannot retard the ignition timing enough under all loads to accommodate the low octane fuel and detonation occurs, the smart’s delicate, expensive “slipper” pistons could be damaged.
(b) Retardation of ignition timing results in increased exhaust gas temperature, thus:
-(b1) The temperature of the exhaust port side of the aluminum head is higher than engineered compared to the cool induction side, putting stress across the casting (think head warping).
-(b2) Grossly retarded ignition can expel un-burned fuel into the exhaust system, thence to the catalytic converter (which in a smart is only a few inches away, not like a few feet away in a larger car), and which can destroy the effectiveness of the cat.

Any of the above could be a cause for warranty denial.

Thank you for that. I've been hoping someone with knowledge of the inside workings would post some details like this.

[Big Panda]

I just 'go with the flow' and use the Premium. Here in Central Indiana, it's generally only .20 more, so at fill-up, it's only costing me no more than $1.60 or so.

And 'just in case' there are any questions on whether I use Premium or not, I have my BP bill to prove it. Since we got our smart at the end of January, I've used BP Premium in it EXCLUSIVELY!

Like I said though, the extra $$ using Premium won't 'break the bank', so why not use it?

[Woody14619]

But wait! Premium fuel -- which cost about 12 percent more than regular at U.S. pumps last month -- is required for the fortwo.

But wait! The EPA mileage tests are being exceeded by most fortwo owners, partially I'm betting because we are using 91/93 octane. I read somewhere that the EPA tests are all done on "regular" octane to keep the test equal across cars. If that's the case, it explains why the EPA rating is under powered for the smart.

And if you do the math, the "12%" increase in cost is misleading. When you're comparing cars doing miles per gallon, you can't just compair dollars per gallon. You need to compair dollars per mile by combining the two values, and when you do, the smart still wins.