mileage

mpj76 · 09-10-2002, 01:13 PM

I know most don't care about it but I'm curious anyway. My car is pretty much stock (1991 LX coupe 5.0 ex-FHP). My mileage in the city is around 19-20 mpg. On the highway at 70 mph its the same. What gives? Here is a list of relevant stuff done to the car. Odometer: 142000. 2.73 gear. 35 psi pressure in tires - 225 60R15.

Heater Core bypassed using bypass CAPS.
spark plugs, wires, distributor, coil - all new
Super Duty T5 tranny
Smog pump removed with relevant hoses.
AIR tube capped ater smog pump removal
Mass air meter and idle air bypass valce cleaned
MSD 6
160 thermostat - temp needle stays bet 1st & 2nd mark
K&N large cone filter
new 02 sensors

302 LX Eric · 09-10-2002, 03:03 PM

Scrap the 160 thermo - wayyyy to cold for everyday driving. You're probably running too cold, therefore staying in rich mode which is contributing to your poor gas mileage.

Move up to a 180 thermo and see how it performs.

E

Maroon 5.0 LX · 09-10-2002, 03:12 PM

I get 19 around town, 26 on the road.

I believe the recommended thermostat is 192°

The Ford (Motorcraft Brand) thermostats seems to be more accurate and last longer than aftermarket types.

09-10-2002, 03:20 PM

Your best bet would be to go with a 180 degree thermostat.

Hozer 88GTConv · 09-10-2002, 03:26 PM

"Contrary to common belief, the computer system does not function best at 160*. Engines operating at this temperature are thermally inefficient." Mustang Performance Handbook

bigblockcoupe · 09-10-2002, 03:43 PM

factory thermostat is 197degrees the stang has been shown to run best at 200 degrees.

09-10-2002, 01:13 PM	#1
mpj76 Registered Member Join Date: Sep 2002 Posts: 158	mileage I know most don't care about it but I'm curious anyway. My car is pretty much stock (1991 LX coupe 5.0 ex-FHP). My mileage in the city is around 19-20 mpg. On the highway at 70 mph its the same. What gives? Here is a list of relevant stuff done to the car. Odometer: 142000. 2.73 gear. 35 psi pressure in tires - 225 60R15. Heater Core bypassed using bypass CAPS. spark plugs, wires, distributor, coil - all new Super Duty T5 tranny Smog pump removed with relevant hoses. AIR tube capped ater smog pump removal Mass air meter and idle air bypass valce cleaned MSD 6 160 thermostat - temp needle stays bet 1st & 2nd mark K&N large cone filter new 02 sensors Last edited by mpj76; 09-10-2002 at 01:41 PM..

09-10-2002, 03:03 PM	#2
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	Scrap the 160 thermo - wayyyy to cold for everyday driving. You're probably running too cold, therefore staying in rich mode which is contributing to your poor gas mileage. Move up to a 180 thermo and see how it performs. E __________________ 1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60'

09-10-2002, 03:12 PM	#3
Maroon 5.0 LX Registered Member Join Date: Mar 2001 Location: Southern Maryland Posts: 471	I get 19 around town, 26 on the road. I believe the recommended thermostat is 192° The Ford (Motorcraft Brand) thermostats seems to be more accurate and last longer than aftermarket types. __________________ '89 LX 5.0 - 5 speed. Original Owner '94 E-150 4.9 Hi-Top Conversion Van '06 Mustang V-6, 5 speed

09-10-2002, 03:20 PM	#4
Simi Stang Guest Posts: n/a	mileage Your best bet would be to go with a 180 degree thermostat.

09-10-2002, 03:26 PM	#5
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	*192 Thermostat** "Contrary to common belief, the computer system does not function best at 160*. Engines operating at this temperature are thermally inefficient." Mustang Performance Handbook __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

09-10-2002, 03:43 PM	#6
bigblockcoupe Registered Member Join Date: Aug 2002 Location: broken arrow Posts: 212	factory thermostat is 197degrees the stang has been shown to run best at 200 degrees. __________________ Rice Haters Club member #68 '93 Cobra 10.20@135 '89 Gt Coupe 12.20@115

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