Black3vGT

I've been running Brenspeeds 87 tune for awhile and while I'm happy with it I can't help but wonder if i'm missing out. So is there a noticeable difference between the 2, or is it not worth the extra $5 or $6 a tank?

Riptide

I couldn't tell a difference between the 91 and 93 brenspeed tunes. Never used the 87 though.

Rock36

I think the only place you will really notice or see a difference is at the track. Even then it might be a difference lost in the variable time spent shifting or in your 60'. I run 93 octane, because I drag race, and that is really the only reason why.

gman73

My guess is about an 8-12 hp difference.

Legion5

Right so its been well known for a very long time that premium fuel SAVES more gas than the price differecence per tank with a retuned engine.

87 fuel was originally calibrated to be the most economical with fuel additives costing 2% of the total price of the gas per octane number.
Currently fuel additives cost .5% of the cost of the fuel per octane number which is the same cost ratio that Europe experiences in the 90s. During that time Europes industrial agencies universally agreed that considering their pricing situation 92 or so octane was the most efficient. Let me repeat that, according to math and science done by Europe in the 90s with the current pricing situation in America means that 92 octane is the most efficient fuel to run to save money.

Currently in Europe the price difference per octane number is .3% of the whole price of the gas, and their worst fuels are rated at 95 octane. Europe is actually poorer than America per capita, and they are running 95 octane over there with fuel prices being about double what they are here, maybe that says something.

With American engines you dont gain as much efficiency by boosting the compression, but certainly 87 octane is the WORST fuel to run in a fuel efficient car if you own one (though you won't see any gains without a tune Revlefty), now in your case 87 octane costs the same as 93 in a performance car to drive the same amount of miles, so ask yourself. Is it worth retuning your engine to potentially save money?
lol

Forum reports back this up by the way as even with our engines which are not designed for the high compression we get the same costs for 87 as 93 in the real world. So everything matches up.

To give you an idea of how much the difference between fuel additives in the 80s and fuel additives now cost. When 87 octane was the most fuel efficient gas, premium fuel was like currently buying $6.00 a gallon racing gas. Obviously the pricing situation has changed.

SlinkyBMX

There is barely any horsepower difference between 87 and 93 tunes. I do notice a slight maybe 1-2 mpg increase with the 93 tho, same driving style.

dschmink

When I had only my intake and tune I still had half a tank of 87. Fueled up and tuned for 93 and I "thought" I felt a little more life in it... but it could be the placebo effect

Elwood

Somebody about a month back did a fuel efficiency experiment. His results said exactly that. The mosteconomic result was running 87 with a CAI and tune. The most fuel efficient result was the 93. However, the less gasyou use is offset by the extra cost of premium.

Legion5

I've heard with our cars all over the place results. Some people save $3 a tank by going to premium and using less gas, I've heard others get slightly worse economically with 93. I've personally noticed a good savings even running FI under the vacume valve cut off with the supercharger off vs the original tune. The reason I noticed was my MPG disapointed me originally now that I'm running a 93 tune it's much better for me.

It really depends on your engine though, for example Honda did an internal test with the Civic 1.7L 4-cylinder. They found that on the highway you lost about 3 cents for every dollar on gas you spent by going regular over premium (87.0, and 93.1 octane RON in the test).

sp44

I felt going from 87 to 93 was a big difference. Haven't gone back to 87. Seemed to me that engine came alive. The tune makes it rev quicker, higher which is why.