Basics for getting good gas mileage with V8
02-26-2008, 08:56 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2007
Location: INDY
Posts: 297
Basics for getting good gas mileage with V8
I woud like to know the basics of getting good gas mileage for a 68' 302V8 4bbl.
Basics like changing the oil ever 3,000 miles.
Sorry, I am a novice at this... Thanks!
Basics like changing the oil ever 3,000 miles.
Sorry, I am a novice at this... Thanks!
02-26-2008, 09:23 PM
#2
4th Gear Member
Join Date: Oct 2007
Location: Central Illinois
Posts: 1,751
RE: Basics for getting good gas mileage with V8
How you drive is the single most important factor. Gentle starts from stoplights. If you are approaching a red light slow down a bit to see if it will turn to green before you get there. Speeding up from a roll is a lot more efficient than stopping completely and then gettinggoing again(don't run the light though). Avoid idling for long periods. It burns a lot more gas than people think. When your secondaries kick in you are really sucking fuel so go easy on that (you do have to use them though to keep them working right.)
like said above.. the best thing is to have a light foot and slow gentle starts. 
02-26-2008, 10:25 PM
#7
6th Gear Member
Join Date: May 2005
Location: MD/WV
Posts: 5,736
RE: Basics for getting good gas mileage with V8
Alot funner on your wallet...
Honeygold summed it up pretty good. Driving technique is the single biggest factor when improving fuel economy. All the new technologies and fancy do-hickies are cool, but if you dont know whats going on on a basic level, your not getting the most out of your car.
Manuals are alot better too
Honeygold summed it up pretty good. Driving technique is the single biggest factor when improving fuel economy. All the new technologies and fancy do-hickies are cool, but if you dont know whats going on on a basic level, your not getting the most out of your car.
Manuals are alot better too
02-26-2008, 10:29 PM
#8
3rd Gear Member
Join Date: Dec 2007
Location: Colorado
Posts: 923
RE: Basics for getting good gas mileage with V8
the way I see it any of the ways to make a big difference in fuel economy (overdrive, tranny swap, different fuel things, rear end stuff) are all to expensive to justify, and just not worth it. If you are truly concerned about fuel economy, drive conservatively, and if that doesnt work, buy a cheap 4 banger honda or something to get good mileage.
02-26-2008, 11:42 PM
#9
1st Gear Member
Join Date: Dec 2005
Posts: 87
RE: Basics for getting good gas mileage with V8
Already mentioned, driving habits and a good state of tune probably do more than anything.
There are other things you can do though.
Read the tire sidewalls. They will say something like "maximumload rating at XX psi pressure". Fill them to that pressure and make a habit of checking them regularly. Cost $0. Tires with less than optimum air pressure cost fuel dollars. Period.
Next, try synthetic oils. Motor oil to start with. Some folks report problems with seals and gaskets leaking some when changing over to synthetics. Some people feel they were leaky anyway and just got worse, others believe older engines just aren't suited to synthetics. Then there are others who have no problems and swear by their synthetic oil.
Change the gear oil in the rear end to synthetic too. Highly improbably that it will leak but very likely it's overdue to be changed anyway. If you have a manual transmission you can change it too. It will likely also feel smoother shifting afterwards too. Don't bother ifyou havean automatic though.
The actual measureable benefit of doing the synthetic swapover is pretty small, despite what the people selling oil say. Butit's there and little things add up.
The one"bolt-on" you can buy to help mileage is a free-flowing exhaust. Exhaust headers, 2 1/4" dual pipes, and your choice of free-flowing mufflers. Depending on how restrictive your current exhaust is you may gain up to 2mpg from this. Maybe, I did once. Side benefits are a nicer sounding exhaust and even a bit more power. Not too cost effective but it helps if your current exhaust is rotten and needs replacing anyway. But if you want your car to remain "original" then nevermind. But if you plan on "hotrodding" the car at all, upgrading the exhaust system should already be very high on your list.
You can certainly gain a couple of highway mpg's upgrading a C4 transmission to say, an AOD. The AOD not only has an overdrive gear but the ability to "lock up" the torque converter in OD. This lets it emulate the way a manual transmission works in 5th gear and approaches the same mileage benefit.
Long term not really cost effective strictly by the numbers. Though there is some satisfaction to doing such a swap and not being nickle and dimed to death at the gas pumps quite so badall the year long.If your current automatic transmission poops out it's not too hard to justify the added expense of an AOD swap. AOD's are addictive though. Once you've driven one awhile it's awful to have to go back to a car that doesn'thave another gear to shift into at 50 mph. Well I think so anyway.
If gas goes up to something like $5 a gallon some of what we are calling not cost-effective will start looking a lot more sensible.
There are other things you can do though.
Read the tire sidewalls. They will say something like "maximumload rating at XX psi pressure". Fill them to that pressure and make a habit of checking them regularly. Cost $0. Tires with less than optimum air pressure cost fuel dollars. Period.
Next, try synthetic oils. Motor oil to start with. Some folks report problems with seals and gaskets leaking some when changing over to synthetics. Some people feel they were leaky anyway and just got worse, others believe older engines just aren't suited to synthetics. Then there are others who have no problems and swear by their synthetic oil.
Change the gear oil in the rear end to synthetic too. Highly improbably that it will leak but very likely it's overdue to be changed anyway. If you have a manual transmission you can change it too. It will likely also feel smoother shifting afterwards too. Don't bother ifyou havean automatic though.
The actual measureable benefit of doing the synthetic swapover is pretty small, despite what the people selling oil say. Butit's there and little things add up.
The one"bolt-on" you can buy to help mileage is a free-flowing exhaust. Exhaust headers, 2 1/4" dual pipes, and your choice of free-flowing mufflers. Depending on how restrictive your current exhaust is you may gain up to 2mpg from this. Maybe, I did once. Side benefits are a nicer sounding exhaust and even a bit more power. Not too cost effective but it helps if your current exhaust is rotten and needs replacing anyway. But if you want your car to remain "original" then nevermind. But if you plan on "hotrodding" the car at all, upgrading the exhaust system should already be very high on your list.
You can certainly gain a couple of highway mpg's upgrading a C4 transmission to say, an AOD. The AOD not only has an overdrive gear but the ability to "lock up" the torque converter in OD. This lets it emulate the way a manual transmission works in 5th gear and approaches the same mileage benefit.
Long term not really cost effective strictly by the numbers. Though there is some satisfaction to doing such a swap and not being nickle and dimed to death at the gas pumps quite so badall the year long.If your current automatic transmission poops out it's not too hard to justify the added expense of an AOD swap. AOD's are addictive though. Once you've driven one awhile it's awful to have to go back to a car that doesn'thave another gear to shift into at 50 mph. Well I think so anyway.
If gas goes up to something like $5 a gallon some of what we are calling not cost-effective will start looking a lot more sensible.
02-27-2008, 06:32 AM
#10
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
RE: Basics for getting good gas mileage with V8
i'd say the first thing to do is to make sure .you have your ignition timing right as well as the carb adjusted.
A pertronix ignition saved me a bit of gallons to the mile. So if you have an old and rotten distributor, you might want to change that.
same with the carb. if it's not driving great it might need a rebuilt.
As simple as the better the engine runs the better mpgs you get.
I have mine down to 15mpg with the occasional foot on the accell. No T-5 at the moment but will convert to that.
A pertronix ignition saved me a bit of gallons to the mile. So if you have an old and rotten distributor, you might want to change that.
same with the carb. if it's not driving great it might need a rebuilt.
As simple as the better the engine runs the better mpgs you get.
I have mine down to 15mpg with the occasional foot on the accell. No T-5 at the moment but will convert to that.