Gas Milage Loss With New Pulley

I just got a 3.4" pulley from the Pulley Boys and I was wondering about how much gas milage I'll lose by installing it. My dad thinks I'll lose about 1-2 (which is too much considering I'm already at 16 mpg with the stock pulley) so he said I should send it back and get the Quikchange one and he'll pay the difference of the 2.

16mpg current? Do you have a heavy foot or something? Holy cow man, thats not good.

16mpg current? Do you have a heavy foot or something? Holy cow man, thats not good.

Actually I drive as "easy" as possible I never really push down hard or anything. Ever since I got the u-bend & resonator deleted my gas milage dropped from about 19-20 to 15-16 or so and noone will tell me why :banghead:.

Stupid question..... Did you reset the DIC? Try resetting it next time after you fill up next.

If I were you I would get the quickchange pulley like your dad said.

Stupid question..... Did you reset the DIC? Try resetting it next time after you fill up next.

If I were you I would get the quickchange pulley like your dad said.

All right thanks and yeah I reset the DIC everytime I fill up and it always drops down again.

Did you get a re-programmed PCM module (ZZP, DHP or Intense) to go with the 3.4" SC Pulley and colder spark plugs? If not then you will have knock retard (KR) at varying times which will ruin the gas mileage even more not to mention putting a hole in or damaging your pistons due to the flame front collisions. The mods will not give you better fuel economy if that is what you are looking for and you will see a decrease.

Do you do a lot of town driving? Next time you take it for a highway drive, Reset it.

Usually if I fill up and right away take it on a steady cruise up to 55-60mph I get about 30mpg, but it drops down to about 22-23 quickly when I take small trips through town.

Right after I changed my air and fuel filters and put in new plugs and wires and PCV valve, I filled up with quality Top Tier 91 octane, I took it for a 15 minute highway cruise at 60mph. Got the DIC up to a little over 32mpg. Not too bad considering these pushrod engines are said to be "primitive" compared to twin cam motors. HA! Take a trip through the ford dealership when you have a chance and take a look at a Ford comperable sedan to the GTP. The stickers say they get like 27 highway and 24 city. Thats not that great in my opinion, my car does better.

Thats another question... You are filling up with premium, right?

Yeah all I do is drive around town, hardly ever on highways and stuff. But I still drive to the same places I drove before and my gas milage dropped a lot so that's not it. And actually no I haven't been using premium for a few months now because the guy that had it before me said he got better gas milage using regular unleaded. I was gonna wait till I installed my smaller pulley (in the next week or so) to switch back to premium. Should I switch back sooner than that? and will that give me better gas milage?

:rolleyes:

See the FAQ at our Tips & Maintenance forum concerning why you need to run premium unleaded gas in a L67 equipped GTP and concerning knock retard which you will get from running regular unleaded. :shakehead

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=664475)

:rolleyes:

See the FAQ at our Tips & Maintenance forum concerning why you need to run premium unleaded gas in a L67 equipped GTP and concerning knock retard which you will get from running regular unleaded. :shakehead

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=664475)

I've read that but I don't get what knock retard is at all except that it lowers performance lol, someone want to explain to me what it is? :)

Knock retard is when the PCM detects engine knock (in this case due to the low octane fuel), and retards the timing to try to stop it. In this retarded timing mode, power output and economy suffer. Running 87 octane is not a good idea, especially if you're modded at all. And as Bob stated, putting on that 3.4" pulley without a reprogrammed PCM to support it is a waste of time and money, and could (and most likely will) hurt both performance and economy as well as possibly do engine damage.

First things first... if the price of gas is a serious problem for you then I suggest you put the stock pulley back on. 91 octane is the minimum rating for a GTP. 92 is preferred for superchargers to prevent knock retard (the number 1 problem with GTP and superchargers in general). Also the DIC is an average estimation of your fuel economy. Driving 70mph and resetting the DIC while coasting will max out the gas mileage. Stop and go driving is hard on GTPs due to their weight class, and your gas mileage will suffer. Grand Prix are great at coasting, use what you got. I have over 147,000 on my 97 GTP and I am still getting an average of 20 in Arizona (hell on earth).

My suggestions:
- High octane (mix in some toluene if it is cheaper)
- check tire pressure/ alignment
- check air filter
- seafoam never hurts
- keep weight to a minimum
- think about a rocker upgrade
- colder plugs (NGX Iridium 6s / PRJ racing wires)
- thermal wrap everything (heat kills)
- ever hear of the acetone trick?

[QUOTE=SNIP

My suggestions:
- High octane (mix in some toluene if it is cheaper)
<<<<<SNIP>>>>>
- ever hear of the acetone trick?[/QUOTE]

I'm game. What are you talking about?

I'm game. What are you talking about?

Reference:

http://peswiki.com/index.php/Directory:Acetone_as_a_Fuel_Additive

Damages Fuel Injectors and Fuel Pumps

As a former mechanic I found this experiment to be of great interest. I was unfortunately a victim to the early testimony here that said acetone does not harm engine parts.

I added acetone as recommended to both my 1996 Honda Accord wagon and saw increased miles right away. I also put it in my 1997 Dodge Ram 1500. After several tanks in my truck (and a little better mileage) I found my number 1 injector showed up as failing. Shortly after that I was talking to John Bedini about the better mileage I was getting and then he said, "yeah, but it will kill your injectors." Then I laughed and told him this just happened to me.

So this weekend I went up to the cottage and my Honda would not start again. Had to tow it home 100 miles and go home early. Turns out my fuel pump was gone. The mechanic asked me, have you used injector cleaner in your car? I told him about the Acetone. He said, Honda pumps never go unless you damage them like this.

So I conclude that this added mileage is certainly not worth the damage it causes. And I suspect that we only read the initial reports here and not the long haul uses of acetone.

Be warned.

Rick Friedrich

Ok about using premium fuel, I switched back to it about a week ago and my mpg dropped about another .5-1 miles. Can someone please tell me why my gas milage is so low? or tell me a way to get more mpg? It's at about 15 right now and my driving habits haven't changed since before when I was getting 19-20 mpg (note that it dropped that low a few days after I got my u-bend/resonator deleted).

ok, lets recap, you changed the plugs wires, fuel filter and air filters, right? And Im hoping you used ac delco parts.

Have you checked fuel pressure to make sure that it isnt unusually high becuase of a return line restriction causing the car to run excessively rich?

How about a vacuum test to make sure that the cat converter isnt partially plugged.

Like the other guys stated, have you checked to see what brand O2 sensor was installed when you had your exhaust work?

Are there any codes being set in the PCM?

Have you tried unplugging the MAF sensor on a tank of gas to see what happens?

A question I often give to those who discredit Acetone is the particulars of its application. Often people feel that acetone is acetone... not true. The acetone you get at home improvement stores and paint shops actually contains other solvents and additives for painting purposes. Only 100% will do. No exceptions. A good place to look for it is under the name "nail polish remover." Also I would advise those discreditors to look into the chemical formulae for gasoline and other petroleum distillates. Much of the gasoline you buy on a day to day basis is not infact gasoline, but contains toluene, and of course, acetone. The application of these chemicals is a means for Big Oil to artificially increase the octane rating of their gasoline, and thus is found in octane booster and fuel system cleaners.

Small amounts is all that is needed. Every car is different so record the pros and cons at each fill up. Never exceed 3.5 oz for every 10 gallons of gas. If these words are still not enough... check into the cheif component of the "Techron" additive from Chevron gas stations.....its acetone.