MPG ?

[Pu241]

Unless you've upped the timing considerably, anything more than 89 octane will not improve your MPG.
I get better MPG with 89 vs 87, but no change in 89 vs 91+ fuel.
Getting ready to head home on a 400 mile run.
One stop, normally no stops, will see what kind of MPG numbers I can pull down.

[All systemz]

91 is the only Ethanol free gas available here, that's the only reason I use it.

[Pu241]

All my numbers are based on 10% ETOH gasoline.

Just a though but you might save yourself some money by blending. When you get to approx a half a tank fill up with 87 10% ETOH, drive till half a tank is gone and refill with 91 ETOH free fuel. In theory you end up with 5% ETOH fuel with an octane rating around 89. Might be more trouble than it worth.

If your going to run 91, take advantage and up your timing!

[All systemz]

Good idea, have to give that a try.

[FestYboy]

^ also, 70mph = 2900ish rpm. i have a shift light set for 3000 rpm and that = 74mph for me.

[navdoc101]

Re-opened this thread instead of continuein' in "What did you do" or starting a new one. I bossted on a new high MPG , & was told not very good...so. I went from a low MPG of 27.8 just after I got 'Tiva to a high of 36.9. Was told to check rear breaks & bearings for drag. Just lifted rear , no drag, tires spin easy & fast. I have replaced plugs , plug wires, dizzy cap & roater, air filter, gas filter, & O2 sensor. Oh, its a '93 EFI, 5sp with A/C. Use A/C almost all the time, even in winter, its Florida!! I DO drive like a crazy man, that will not change!!! Seafoamed tank & intake. Mostly in city driving. What can I do next? Any help will be apprectiated! Thanks!!!

[Pu241]

Driving like a crazy man might mean that 36.9 MPG is about all you can expect.
Nothing wrong with that, if you accept/like your driving habits as they are.
If you want more MPG it will require a change in those habits.
I have to drive like a near sighted grandmother to reach the MPG I do.
It's hard work and probably not as fun as driving like you do!

[navdoc101]

Thank you, a straight answer!!

[71Montego]

I drive a 91 Auto with a BP and daily driving 70% hwy I get 25 -26. I hit 27 on a long trip but was forced to keep up with trafffic and drive 65-70MPH.

[neanderpaul]

Re-opened this thread instead of continuein' in "What did you do" or starting a new one. I bossted on a new high MPG , & was told not very good...so. I went from a low MPG of 27.8 just after I got 'Tiva to a high of 36.9. Was told to check rear breaks & bearings for drag. Just lifted rear , no drag, tires spin easy & fast. I have replaced plugs , plug wires, dizzy cap & roater, air filter, gas filter, & O2 sensor. Oh, its a '93 EFI, 5sp with A/C. Use A/C almost all the time, even in winter, its Florida!! I DO drive like a crazy man, that will not change!!! Seafoamed tank & intake. Mostly in city driving. What can I do next? Any help will be apprectiated! Thanks!!!

Per htchbk's instruction, part, and installation I netted about 3-5 mpg better from an intake manifold mounted temp sensor.

[200KGPGTP]

^^^Detailz!?

[Pu241]

Have a BP with E-series tranny and can consistently hit 44 -44.5 MPG.
Never broke 45 MPG though!

[71Montego]

The sensor is a thread and plug in one. It did not seem to help me. Here is one. Also called an engine Management sensor.

http://www.ebay.com/itm/Original-Engine-Management-9305-Coolant-Temp-Sensor-tx18-1oz-/280809198575?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3AFestiva&vxp=mtr&hash=item41618853ef

[Darlo]

I DO drive like a crazy man, that will not change!!! What can I do next? Any help will be apprectiated! Thanks!!!

This is like somebody who is SUPER FAT asking everyone how he could loose all the weight, "but dont ask his to stop EATING 8000 Calories a day, cause that will not change"! What else can he do?

If you are not willing to do the thing that will see the largest improvement (aka driving nicely, not really like a granny), which would net you 5-10mpg, why would you want to spend all this time figuring out how to save 1mpg?

Seriously, if you look at my Fuelly badge, and then look at your own........Doesnt the fact that mine shows a 66 fill AVERAGE of 16.4mpg more than yours in the EXACT SAME CAR (minus AC) get you wondering if you should change just a little? (I still had a lot of fun with mine sometimes (even in the snow), but I didnt drive nutty all the time)

[Oren09]

I'll chip in on this to give my statistics.

My fuelly so you can analyze if you like:

http://www.fuelly.com/driver/oren09/festiva-2

I have an all-time average of 39.5 MPG.
This includes a 4000 mile trip to Montana where I averaged 44-52MPG.
When I first got my car running, it ran like crap. Blowed smoke everywhere and pretty much ran on three cylinders. It got 24MPG the first tank. Mileage went up to 31 from there and has never gone below 30 since. After replacing my cylinder head, I began to average about 35-37MPG. I started using 89 octane gas and my mileage increased a few MPG. I think my timing is off. My engine makes a funny noise under load- like hills in 5th gear. I have a timing light but can't get it right...
I run on the highway at 55MPH. I don't remember when I started doing this, but when I have a mix of city/highway I get about 37-40MPG.
When I run straight highway at 55MPH I can get 47-52MPG.
Straight highway at 70-75MPH gives me about 37MPG. That is quite a difference.

This is what I've recorded and noticed after nearly one year of ownership and 18,000 miles.