Gas Mileage

[1988GTU]

AC Rapidfires Part # 6  It should burn hotter than the rest which is good.
OR
Delco's R44LTSM.  Cheaper but will work fine also.  Might require a change out sooner than the Rapids, but not by much.

[Cliff8928]

(john266 @ Nov. 08 2008,21:57)QUOTEConsidering the spark plug situation, I'm gonna toss the copper Autolites and go with AC's.  The question is which ones?  I work at Advance Auto and the Beretta can take one of three plugs for the '90 model:

AC Rapidfire Part # 6
Standard AC Copper Part # R44LTSM6
Standard AC Nickel Alloy Part # R44LTSM

Which is the best bang for the buck?
The only difference between the R44LTSM and the R44LTSM6 is that the "6" is pre-gapped to .060".

If i remember right, the current design of Rapidfire is actually platinum.

You can also use the ACDelco 41-101 Iridium plug that comes in the newer 3400 and 3500s.  They're a little more expensive but less than the other iridium plugs available.  They're made by NGK.

[john266]

I changed the plugs yesterday and put the R44LTSM's in it.  To my surprise, the plugs seemed to quiet the piston slap that is so common to that motor.  By no means put Autolites in a 3.1 like the moron who did before me! LOL

[yellow3800]

Think of this, DRIVING METHOD:  The best gas milage occurs in TOP gear at the lowest manifold pressure.  We don't have vacuum gauges by stock, so just keep it as slow as possible in top gear.  If you live in mountanous terrain like I do in TN, then I must keep my manifold pressure equal on the down hill [car speeds up] and slack off when climbing the next hill all to maintain as if the car were in fact driving level all the time.  if the hills are too steep to do this, then I add more going down hill, and hold it going up hill, often times, more torque is needed to climb a big hill, and then speed must be increased to obtain a higher torque to maintain the torque needed to climb the given hill.

Now If I could just learn how to properly select an altitude to fly an airplane at, I'd be smarter on this topic.

Andy

ps.  I found that prev. owner put platinum plugs in my 89GT, I get >22mpg, but probably NOT over 25mpg.

Definately STAY AWAY from alcoholic fuel.  I don't think our V6's benefit from that, the quads probably do.

[Money pit Beretta]

A 4spd auto would help alot and you need to fix the rear main seal anyway(just a thought,I bet it's more work than you wanted to do). The 95 3100/4T60E gets better MPG than my old 90GT's 3.1/3T40, but I miss the low end TQ and the better gears(less the fact that the 4T60E has a better overdrive). What brand of wheels are in your sig photo John?

[john266]

The wheels on my car in the picture are some brand called Kazera.  I bought them off a friend of mine.  If someone is interested, I might sell them to get them out of my building.

[Money pit Beretta]

Have you come up with a plan for more MPG? I'm looking to buy new wheels. Mine are a pain to get the lugs off and are starting to flake.

[john266]

Yeah, the gas mileage thing is goin pretty good.  I changed the plugs back to the AC's, and got my motor mount fixed.  Right now the car is getting 26 MPG, which is a slight improvement.

As for my wheels, they are 16", and they are in pretty good condition.  I think one of them has a little curb rash, but nothing really noticeable.  Right now they have a set of low profile Pirelli P-Zero tires on them, with probably about 5/32 remaining.  I don't really need them any more, because I put my stockers back on and it rides like a Cadillac now.  Just let me know, and maybe I can post some more pics.

[Money pit Beretta]

Sounds good on the pics, I'll take a look and we can work out everthing after that. Are the lugs easy to get off? They look almost the same, don't they?

[yellow3800]

Correction, I just figured my full tank of gas of REAL gas [87 NO alcohol] and got 27.3mpg by driving 23miles per trip, averaging 50mph.  [no air conditioning use]

89GT 170k, avg tire pres.

so far, and at least in TN, Texaco and Conoco/Philips are the only two gas stations near me that don't spike their gas.  BP used to be good, but all of our stations now serve 20 proof.

Andy

[john266]

Money pit, have you changed out your front lug studs out to the longer ones yet?  I had to change mine to the 54mm length (if I remember correctly) to accomodate the wheels.  As for the lugnuts, I had to put "low profile" tuner nuts on it to fit into the holes on the wheels.  All the lugnuts require a key to take off.  I have two sets of lugnuts (one set brand new) to fit these wheels.  Send me an email at 1FastS10@comcast.net and we'll discuss it if you're still interested.