Bob
Banff is in Alberta not British Columbia
Ed
Bob Spidell wrote:
> Randy,
>
> What difference did you notice--besides probably slightly lower mileage with
the ethanol blend--assuming same octane ratings? Is your car harder to start
with ethanol blend? Does it idle/run rougher? Is power output down (you'd
probably have to put it on a dyno to get an objective rating)?
>
> I just put 4,000 miles on my BJ8, with all types of gas, and didn't notice
any difference from tank to tank. We ran the usual ethanol-blend 90/91-octane,
ethanol-free 91-octane, 92-octane and even 94-octane gas (obtained in Banff,
BC of all places). No difference that I could ascertain, but power was down
overall since we were mostly at 3K+ feet of altitude. Unless the car is
built/tuned for higher octane gas you're wasting money--and, possibly, hurting
the engine (but, hey, it's fun to throw it in there anyway). My Mustang will
run anything from 87-octane on up--almost always an ethanol blend--and the
only difference (on low test) that I can tell is that it's arguably slightly
rougher and has just a hint of hesitation when I punch it (of course, the ECM
makes necessary adjustments). I put 93-octane 'pure' gas in once just for
yuks, and honestly couldn't tell a difference over premium (but, I didn't dyno
it or take it to the track).
>
> Octane rating is octane rating, regardless of the blend. Energy content may
vary--lower octane gas is allegedly higher due to more 'explosive'
combustion--and with different blends (i.e. ethanol) the vapor pressure may
vary which may affect starting and hot/cold weather starting and, possibly,
vapor lock. I believe the energy content of ethanol is less--as manifested in
reduced mileage--but its anti-detonation properties (i.e. octane rating) are
better than pure gasoline.
>
> I'm not a fan of ethanol-blended gas--I think it's a scam for the corn
lobby--but, honestly I can't find fault with the blended gas (at least at
10%). Yes, I know ethanol is corrosive and absorbs water, but I've had no
problems with either of our Healeys whatsoever (both our tanks were lined with
Bill Hirsch gas tank sealer, FWIW). I have noticed a bit of a stumble when
first starting after a shutdown in hot weather, which I attribute to mild
vapor lock and may well be due to the ethanol (but I can't prove it).
>
> We've tracked mileage for the 16 years we've been taking extended trips in
my BJ8, and it hasn't varied: 23mpg @ 60mph (flat terrain), 19mpg @ high-speed
or mountainous terrain, 17mpg in stop-and-go city traffic.
>
> Bob
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