Gas mileage down after Superchips

[quadc7]

Made the following changes to my 2002 E150 4.6L, K&N air: changed rear gear from 3.55 to 3.73, tires from Michelin 2.35-75R15 LTX M&S to Firestone Destination LE LT2.35-75R15, NAPA Sensa-Trac shocks, Superchips Perf/Tow setting. Gas mileage was averaging 18.5 with stock package, Superchips 87 octane setting. I knew it would go down some, but now averaging 16.2.

I pull a camper during the summer months, that's why I changed the gear, shocks and went with a heavy duty tire. Oil is Mobil 1 5W-30, synthetic in transmission and rear gear. If I cannot get it better, prefer to change back to 87 octane especially with prices going up. I drive 30 miles one way to work, and the reduced mileage is starting to get expensive.

Any suggestions are welcome, if I could find out what settings to use for shift points and pressure, prefer to change back to regular gas.

[dieselman]

I'd stick with the 91 octane setting. Keep in mind, superchips is a performance option, it's not meant to give you better fuel economy. It just happens to be a side effect from some superchips users. You can also take the superchips tune off your truck, and run a tank or two of fuel to see if the gear change is what made your mileage drop. I doubt it is the reason, but you never know and it worth a check. For shift points I'd only raise it 400rpm per shift, so there won't be excessive 3-4 shifting around town.

[coolbikr7104041]

i have a 97 ford f350 dually with an automatic tansmission and 460 engine is it possible to put in a diesel into it? and if so with what engine should it be replaced with or where can i go to find out if i can?

[supremev10]

Try the MPG-CAP which can get your engine burning octane 87 like getting same power of octane 91 because it burn more complete, plus it help run 10 to 15% more mileages also cut down 75% emission sure get test only smog check passed so easily. cost is $2.50 each for each 15 gallons fuel, my 97 v10 6.8L trial it for couple months and just pass the California Test only smog check last week without changing any parts nor oil

[portdog4021]

im suprised to hear your gas mileage went down mine went up when i installed the chip. my mileage went from the mid 18's to the low to mid 19's. you can try changing the setting to economy that should help. hopefully that works for you

[Heavy_Metal]

Ahhh, you think the gear ratio change might have something to do with that? It had nothing to do with the tuner. You changed to a lower ratio resulting in higher engine speeds contributing to your lost mileage. You will never get the mileage back since you changed ratios.