my tc hates 87 octane

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my tc hates 87 octane

August 12, 2012, 07:50:37 PM

so gas went up this week, to $4.29 for 93 octane. i was feeling cheap, so i fugured i would flip the premium switch off and run the cheap stuff. well its the first time in a long time of doing so, car runs like . cant wait until the tanks is empty. i will do what ever it takes to buy premium next time!

my tc hates 87 octane

Reply #1 – August 12, 2012, 08:39:46 PM

I had a few cars like that. I had a 92 mark vii that only ran good on 89 anything else and the car ran like garbage. Also had a 87 Chevy celebrity that wouldn't run decent unless the good stuff went in. Weird.

my tc hates 87 octane

Reply #2 – August 12, 2012, 09:13:49 PM

4.29 for preemium i wish it was that cheap around here, I pay 4.50 for Regular.

my tc hates 87 octane

Reply #3 – August 12, 2012, 10:18:31 PM

So, was regular what? $0.20-$0.30 cheaper? You saved a whole $4-$6 on that tank? Spend the $5 extra bucks next time.

my tc hates 87 octane

Reply #4 – September 09, 2012, 08:40:15 PM

im running a 50/50 mix of 93 and 87 :lol:

with switch on regular. running good so far, at 340 miles and still between 1/4 and 1/2 tank :D

my tc hates 87 octane

Reply #5 – September 09, 2012, 10:50:41 PM

The TC was never designed to run on a constant diet of 87 octane. It was designed for premium. The octane selector limits boost to 10 LBS and removes 6* of static timing. This in turn when switched to REG FUEL will remove app 20-25 HP from the little 2.3. And that is a lot of PONIES. So bottom line it runs like !!!

:hick:

my tc hates 87 octane

Reply #6 – September 10, 2012, 01:06:14 PM

The four automatic '87-'88 TCs I owned never made more than 9-10 psi reguardless of where the switch was set, BCS was mostly there for looks...

my tc hates 87 octane

Reply #7 – September 10, 2012, 02:36:08 PM

Quote from: TurboCoupe50;397913

The four automatic '87-'88 TCs I owned never made more than 9-10 psi reguardless of where the switch was set, BCS was mostly there for looks...

Yeah Violet, being a 5-speed and with a Gillis boost valve routinely makes 15-18 lbs., just not squat in first.

my tc hates 87 octane

Reply #8 – May 14, 2013, 04:16:34 PM

Been running 93 in the TC Bird since I changed the head out to a N/A head from a Ranger. Which bumped the compression up from 8:1 to 9:1. Mine actually requires 93 now. As most of you probably know the more you compress the A/F mixture (with engine compression or boost) the more it heats up, and the higher the octane needs to be to stave off detonation. So, after that I could only boost to 6-7psi on 87 octane before detonation started. Once I started using 93 octane I could then boost to 15-17psi (turbo limited), and with no pinging whatsoever. That 1 point of compression not only added a noticeable increase in power under boost, it also changed the sound of the entire engine under boost, making it sound much more fierce. Requires 93+ from then on out though. I think I'm going to stick with the higher compression ratio N/A head during my 2.3T build, and just run 93 and 115 octane from now on. Having to spend the extra $5-6 for a tank of 93 each time doesn't hurt my feelings any.

my tc hates 87 octane

Reply #9 – May 15, 2013, 09:20:04 AM

Ah the premium fuel discussion... Usually premium is 20-30 cents per gallon more. Which is odd, 20 years ago it was the same thing...which 20-30 cents per gallon on $1.25 gas is a pretty big increase...nowaday...really.
You save 5% in this days fuel cost. 5% isnt worth the performance and mileage loss...its that simple...

Thanks,

Travis

my tc hates 87 octane

Reply #10 – May 15, 2013, 12:11:49 PM

In what kind of service station are you folks finding 93 octane?
Here in Phoenix, all I can find is premium that is rated at 91octane.
Ron

my tc hates 87 octane

Reply #11 – May 15, 2013, 03:53:52 PM

It varies by state. In some states 91 is premium.

93 is what they sell here as premium, all throughout North and South Carolina. Never even seen 91 around here. Our gas runs 87>89>93>115.

There's still octane rating of 115?????

Reply #12 – May 17, 2013, 07:31:44 PM

WOW!

Big B. Here in the Kansas City Metro there hasn't been any such thing as 115 in many, many years! Just 87, 89 & 93...I THINK!! LOL!

I used to have a 1971 AMC Ambassador Police Special back in the early 80s that would NOT even run on anything less than that PREMIUM, baby!

When I had my 67stangfastback inline 6 from the mid 90s to early 2000s, it ran just fine on the cheapest stuff I could find. Now, my 88 Cougar 3.8 will run ~ok~ on the cheap stuff, but better on mid-grade, of course. It makes little difference on premium grade, though. But it absolutely HATES ethanol!!!! My full-size 89 Bronco 4x4, on the other hand, is an absolute alcoholic!

But it's somewhat similar to the Kitty when it comes to gasoline grades. But, it does do MUCH better on Premium. I guess that's what I get for breaking that brand NEW 302 in on Premium, eh? LOL!

my tc hates 87 octane

Reply #13 – May 17, 2013, 09:21:27 PM

we have a 10% ethonal mix here state wide. lost about 10% mileage when they did the switch. I didn't notice much difference in power, but I can run 16 degrees ttiming.without any pinging on "85" grade fuel.

the difference in.fuel grade has to do with oxygen levels at different elevations. here our premium is 91.and we have 85 87 and 89 grades at most gas stations. I'm at about 4500ft elevation here. although, I have never noticed any difference.going down to sea level.

some of the mustang guys here claim a 1/2 second difference in quarter mile when they.run at Vegas compared to here in Utah.

my tc hates 87 octane

Reply #14 – May 18, 2013, 10:34:55 AM

Carbon build up is common on older engine...which will raise the compression of the engine...sometimes requires more octane to be happy....ie...needs 87...but is happier on 89..

Travis