Low Buck MPG improvement?

[marklj]

Overheated engine repair project completed. (Replaced blown head gasket, cylinder head resurface and valve job.)

First tank of gas netted 31.25 MPG. That's driving around Athens, GA making my service calls.

Things I’ve done so far that should help MPG:

Valves adjusted meticulously.
Fresh spark plugs gapped at 1.1 mm
New air filter
10w 30 full synthetic oil
Timing set at 22 degrees. Had to back off 2 degrees from the 24 degree spec due to spark knock.
Vacuum advance replaced and rerouted vacuum lines for part throttle vacuum signal at all times.
EGR disconnected. (No part throttle spark knock)
Carb cleaned and ran Berryman carb cleaner through the tank. (Idle mixture screw still sealed. Running at little lean at idle right now.)
Tires at 40 PSI
Cruise control used whenever possible.
No extra weight in the trunk.
Rain X ed windshield. ;-)

Any other suggestions for low buck MPG improvement?

[Doward]

Stop using the cruise control.

Speed up slightly on downhill portions of your journey, and use the extra momentum to help get you up the next hill

Header + no cat + mandrel exhaust will help improve volumetric efficiency - meaning better mileage AND more power

[Dr_Snooz]

Header + no cat + mandrel exhaust will help improve volumetric efficiency - meaning better mileage AND more power

I know that every hot rod mag likes to print articles telling you to improve mileage by spending a fortune on high dollar performance mods, but it's patently untrue. If you want better mileage, DECREASE volumetric efficiency. You want to move less fuel through the engine, not more.

I think the hypermiling crowd can probably give you the best tips for improving mileage on the cheap. Some of them can be pretty clever. Some can get you beat up on the roadside by irate drivers infuriated by you driving 58 mph in the fast lane at rush hour.

[Doward]

I know that every hot rod mag likes to print articles telling you to improve mileage by spending a fortune on high dollar performance mods, but it's patently untrue. If you want better mileage, DECREASE volumetric efficiency. You want to move less fuel through the engine, not more.

You can move less fuel through the engine by increasing VE, requiring less throttle.

The problem is, most want to enjoy that newfound power, and floor it everywhere, which obviously decreases the overall mileage.

Ultimately, you want to try to maximize torque near your cruising rpm

[marklj]

33.89 MPG on a trip to Atlanta and some around town driving.

Tuned headers and free flowing exhaust would no doubt help power and MPG. But it not in the budget right now.

Possibly Denso IW16 Iridium Power Spark Plugs?
Wonder if the $8.50 a plug would be worth it in MPG?

http://www.densoiridium.com/faq.php
Q. What kind of testing has been done?
A. Iridium Power has been tested in many arenas. The most common area of testing has been on the track. There are currently many people using the plugs in import drag racing, with results being quite favorable. Some racers have seen E.T.’s decrease by a tenth and less fuel consumption during a pass. Circle track racers using the plugs notice better acceleration coming out of corners and more consistent idling. The other area where the plugs have been tested are on good old dynos. The results have indicated horsepower increases over stock plugs of 2-3 Hp in a naturally aspirated engine and 27 Hp in a supercharged/turbocharged engine as seen in the January 2003 issue of 5.0 Mustang & Super Fords magazine*.

*Copies of 5.0 magazine article and/or various applicable dynographs are available from DENSO upon request.

[86-lxi]

Overheated engine repair project completed. (Replaced blown head gasket, cylinder head resurface and valve job.)

First tank of gas netted 31.25 MPG. That's driving around Athens, GA making my service calls.

Things I’ve done so far that should help MPG:

Valves adjusted meticulously.
Fresh spark plugs gapped at 1.1 mm
New air filter
10w 30 full synthetic oil
Timing set at 22 degrees. Had to back off 2 degrees from the 24 degree spec due to spark knock.
Vacuum advance replaced and rerouted vacuum lines for part throttle vacuum signal at all times.
EGR disconnected. (No part throttle spark knock)
Carb cleaned and ran Berryman carb cleaner through the tank. (Idle mixture screw still sealed. Running at little lean at idle right now.)
Tires at 40 PSI
Cruise control used whenever possible.
No extra weight in the trunk.
Rain X ed windshield. ;-)

Any other suggestions for low buck MPG improvement?

When you adjusted your valves did you go for more or less lash? I did mine right in the middle of the factory specs.

[marklj]

I went with the smallest gap secification. Less lash = more lift. .005 intake, .010 exhaust as I recall. Probably one of those splitting hairs type of things.

[86-lxi]

Cool thanks, I'm all about the splitting hairs type of adjustments. If i can get .5 more MPGs I'll do whatever it takeshaha

[g.frost]

You are doing good pushing 34 mpg with mostly highway miles. Summer fuel & warm temps my stock 88 DX will do 35-36mpg highway tank after tank. You don't have to 'hyper-mile' to get these numbers. 70-75mph is no problem, the DX is geared for highway cruising. I run synthetic oil, and Red Line MTL synthetic in the transmission.

If Iridium plugs would actually help MPG, I might consider replacing the old tried & true V-Power plugs. 100% stock, even the old 13 inch wheels.

[g.frost]

..............
If Iridium plugs would actually help MPG, I might consider replacing the old tried & true V-Power plugs. .........

I just replaced the NGK BPR5EY-11 (7 years, 24K miles) they looked good, clean and only slightly worn), put in NGK BPR5EGP Platinum tip.

Idle is up about 50rpm (750 to 800) smoother, and throttle response off idle is improved. At $2.99 each vs. $2.29 for the V-Power, this is a good cheap upgrade. It will be a couple months before I see if there is a MPG improvement.
I'm already sold on the improvement.