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So how much can you get on a tank?

10291 Views 115 Replies 48 Participants Last post by  mrodgers
I've been toying with hypermiling since a lot of my driving is city or rural, not highway. Best I've stretched a tankful so far in my '04 Jetta, 2.0 is 376.5. How about you?

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Just filled up today and I got 303.4 mi on 11.516gals. That gave me a little better than 26 mpg which is up from just under 24 the last tank full. I eased up on the throttle a little this time too and had more highway this time. This with a bad cat waiting for the dealer to replace.
i can get about 350 miles on a full tank of 93 octane and im not chipped yet. just gotta keep it outta boost alot, which is hard to do with a stock turbo lol. i only have 39K miles on my 02' :).
Do you think going from regular oil to full synthic will give u a little better gas mileage? Also whats the chip sopose to do for gas?
yes engine will spin easier, synthetic has alot better lubrication properties. and burn fuel more effectively. thus better mpg.
Winter fuel contains additives to increase the volitility of the fuel (it's ability to vaporize). They do this in northern states so that your car actually starts in the morning... If you use summer blend during the winter, your car will not start, guaranteed.

Anyway, these additives are a higher octane, however they contain much less BTU's (in other words, heat energy). This means that although you could theoretically increase boost and/or advance spark timing to make up for this loss in power, nobody does... Which is why you get, on average, 4% worse fuel economy using winter blend fuel... Due to having far less heat energy.

...Which is also why fuel with ethanol gives you less MPG's. Ethanol (the same kind of alcohol you consume) contains high octane, but less BTU's, like the additives in winter blend fuel (also alcohols, with some other ''good stuff''). Ethanol is a lot more corrosive too, which is why people try and seek out ethanol-free fuel.... But thats for another thread.

And I know someone is going to say ''What about E85 and methanol injection'', so I'll answer that too. When you use alcohol injection, it bypasses the MAF, and isn't calculated in with fuel delivery though the injectors... You're ''sneaking it in'', so to speak, because its un-accounted for. So although it has less BTU's than gasoline, it has a higher octane. You get the benefit of using gas, with the addition of a higher octane... Meaning you can advance spark timing and/or boost more so than if you had a lesser octane mixture. And pure E85 (85% ethanol) again, has less BTU's, but can achieve a ton of power because its octane is well over 100. But fuel economy is garbage...

Ok. Done now lol.
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