graydawson09

I am trying to calculate how much it will cost to fill up the tank in a '65 Delta 88 w/ 425 V8, but don't know how many gallons the tank holds. Someone help?

Thanks

MDchanic

The '65 SPECS guide says 25 gallons.



- Eric

edit: D'oh! Wrote wrong year.

jaunty75

Remember, though, that you will never completely empty the tank, even if you drive it until it "runs out of gas." I removed the tank from my '67 Delta to replace the fuel gauge sending unit, and I saw the way the system works. The fuel pickup pipe extends down from the top of the tank and terminates about a half-inch from the bottom. I'm sure the idea here is to prevent any crud in the tank that accumulates over time from getting sucked into the pipe. There is a sock filter over the end of the pipe to help prevent this, but if the pickup were on the bottom of the tank, the crud could clog the filter.

Anyway, I did a little math given the surface area of the bottom of the tank and the 1/2-inch height of the pickup pipe to calculate the volume of fuel still in the tank when the level falls to 1/2 inch. It came out to be about 2 gallons.

So your usable capacity is about 23 gallons, and you're probably likely to fill the tank before you run out of gas, meaning that you still likely have two or three gallons in the tank when you do the fill-up. So this means that if you're the type who runs the tank right down to E before filling up, you're probably putting in at most 20-22 gallons. At the current price around here of $2.99 per gallon, you're talking $60-$65 to fill it.

MDchanic

Sorry, Jaunty, total typo - too early in the morning.

That image IS from the '65 book.
I just typed '67 by mistake. Twice.



- Eric

graydawson09

Thanks, guys... very helpful!

Allan R

Well, for what it's worth here's the info from the 65 CSM

graydawson09

Any idea about mpg with a 425 V8?

MDchanic

As they say over at the jewelry store, "If you have to ask, you can't afford it."

- Eric

jaunty75

It's going to stink compared to cars of today.

I'm curious. Why all this concern about cost to fill the tank and gas mileage? Most people buying a vintage car don't car about these sorts of things because they're going to put only one or two thousand miles on it a year. It sounds like you're planning to use this car as a daily driver.

I've got a '67 Delta 88 with the 425, and you're mileage is going to be typical for a gas-guzzling, big block Oldsmobile engine of the '60s. You might get 15 mpg on the highway, low teens in the city.

Your alternative in trying to get a high mpg commuting car is to get something like a three or four year old Honda Civic. But even this would cost you something like $10,000. I'm guessing that, whatever you're paying for this '65 Delta, unless it's a convertible in beautiful shape, is well less than this, probably less than half.

The $5,000 or more that you save by driving the Delta buys A LOT of gasoline, and you're talking here the additional cost of filling the tank, not the total cost, as the Honda needs its tank filled once in a while, too.

Let's do some simple math assuming round numbers. Let's assume the Delta 88 gets 15 mpg and the Honda 35. That's 20 mpg difference. Now assume a gas cost of the currently roughly $3.00 per gallon around the country. $3.00 per gallon divided by 20 miles per gallon equals $0.15 per mile. That's how much extra it costs you to drive the Delta 88 as far as fuel cost goes.

Now divide the $5,000 that you saved by buying the Delta in the first place by the fuel penalty cost. $5,000 divided by $0.15/mile equals 33,333 miles. In other words, you would have to drive the Delta 88 over 33,000 miles to use up the savings in buying the car in the first place versus buying the Honda. Are you going to put 33,000 miles on a '65 Delta 88 before some other circumstance comes along and you sell it or for some other reason no longer use it as your daily driver?

And all this assumes a $5,000 cost difference for the two cars. According to the Kelly Blue Book, 2009 Honda Civics right now retail for $10,000 to $16,000. At the same time, maybe you're getting this '65 Delta for $2,000 instead of $5,000.

Maybe it's more realistic to say that you'll pay $12,000 for a decent, used, four-year-old Honda Civic and only $2,000 for that Delta. That's a $10,000 difference, not $5,000, so you're talking almost 67,000 miles of driving the Delta before the cost of buying it plus driving it exceeds the cost of the Honda Civic plus the gas to drive IT for 67,000 miles.


I have no idea why you're asking these questions. But no one asks about mileage and fuel tank capacity if they're planning to drive the car 100 miles a year. So the natural assumption is that you are planning daily driver use. Sorry if I'm wrong and this bored you to death!

graydawson09

...and your point is, Eric? You don't know what my salary is, so if you don't have anything that isn't ignorant to say, don't bother. I'm trying to get some information on a car and you're being a fool... go annoy somebody else.

MDchanic

Wow, Jaunty, not too busy today?

In my case, I prefer to measure in Smiles per Gallon .

(That Honda would come in with a negative number).

- Eric

jaunty75

It's something to do while I've got the Mecum Auction on in the background.

We're going out for ice cream, later!

graydawson09

I'm just asking a bloody question! This is a forum, isn't it? I don't understand why YOU'RE so concerned as to why I'm asking a simple question... what is the big deal? I'm just asking because I'm curious and want to hear from the owners of these cars... not because I'm "going to use it as a daily driver" or put over 1,000 miles on it a year. So, please, don't assume things and tell me I can't afford to drive it, like the idiot above. Thanks for the information.

MDchanic

Wow. I can't be sure, but from that response I'd guess about 200-250 a year, and that you're a lawyer.

Sorry, my wife's out of town, so you'll have to do.

If you want my actual opinion, when I drove a '68 Delta 4-door with a stock high-compression 455 (very comparable to your setup) every day commuting to Manhattan from Staten Island, I got about 6mpg, and I enjoyed every one of them.

- Eric

jaunty75

Yes, and we're just providing a "bloody answer."

Cool off. We're just having fun here. No one has intended any harm. You're way overreacting.

You're right. It IS a forum. But that means we ALL get to talk, not just not you. This is not a question-and-answer session where you pose the questions and we provide the answers like robots. This is a pleasant CONVERSATION over a couple of cold beers. You would do well to learn this.


And next time, no need to quote my whole post and then get mad. Just get mad. Takes up a lot less screen space that way, and we'll know what you're talking about.

jaunty75

And that was probably downhill!

graydawson09

You sound like a middle-aged nobody that lives with his mother and gets a sick pleasure out of antagonizing people over the internet.

Allan R

In all honesty, and not trying to be a wise **** here, I'd suggest that depends a lot on how you drive it, where you drive it, and avg speed. Other than that, I don't have anything of value to add.

MDchanic

Amazing work, Kreskin.

In fact, I am "middle aged."

I guess I would live with my Mom if I could, but seing as how she's been dead over twenty years, that would be a bit, er... "Norman Bates-ian," don't you think?
Instead, I live with the usual wife who thinks that we don't run out of money until we run out of checks, and a kid who thinks the internet is a physical place to hang out.

You are right, though, that I am getting a sick pleasure from antagonizing you, mostly because it's so darned easy.

All American cars from the sixties got about the same mileage, anywhere from 6 to 25mpg, depending on size and weight, and how they were driven.
Cadillacs would more often fall into the single-digit range, big Oldses and Buicks just above them, Cutlii and their ilk about 14 to 18, and little Novas and Valiants as high as 25 on the highway.

- Eric

graydawson09

Thanks for the input, Alan. I appreciate your cordial approach.

oldcutlass

You gotta love the direction that these conversations go. Some people are like my wife, no matter what you say, if there is anyway of taking it the wrong way, she will find it.

MDchanic

My wife never told me she had a sister...

- Eric

oldcutlass

I bet she has many!

jcdynamic88

to answer your question,i get a strong 17 mpg at 70mph hiway 425 q-jet in my 66 88 convertible and about 12mpg local. i believe the q jets are substantially better than a 2 barrel as long as you stay out of the secondaries,jc

Allan R

That's really respectable mileage from older technology. I agree the q-jet is a very decent fuel handler. Sounds like you keep your car very well tuned and maintained. That's another thing that goes a long way to performance and mileage.

jcdynamic88

i'll admit i was pleasantly surprised, but i cant help but wonder what a 200r4 would do for my mileage.ive never checked the gear ratio but i think it could stand to be higher.those figures were consistent on my trip to and from lansing,mi from mass in 97.

Red Delta

I'm printing this out in a nice font, putting it in a cheap frame and hanging it on the wall.

jaunty75

If you send it to me, I'll autograph it.

jaunty75

Cheap frame?

Red Delta

You want me to spend righteous Olds maintenance cash on décor?

oldcutlass

I like the fuzzy math, the fly in the ointment is no one has figured out what a $2-5k car is going to require in parts to become a reliable daily driver. It can easily run the difference in cash on Jaunty's equation.

However again the big difference here is smiles per mile. That's the real reason we do what we do. Oh yeah, and the voices tell us to.

navvet

I have put on my flack jacket and helmet prior to writing this...(JUST IN CASE).I spent a great deal of time and effort rebuilding my carb doing a correct tune-up, replacing the fuell pump and lines and always making sure I use top quality oil and filter. My tires are a good touring type and I keep my tire @ 35lbs. With all that said my 64 88 with a 2 barrel 394 gets 17 on the highway and 10-12 city. If I kick it down around the city it is about 6 mile to the gallon. Like any car how hard you drive effects MPG. The car has done a 1000 mile plus road trip and I was very easy on it to gain the best possible MPG. During the trip it averaged 17 mpg.

jaunty75

I was assuming the $2,000 Delta 88 already was a daily driver, or close to it. Certainly a $5,000 '65 Delta 88, going to the other extreme of my example, ought to be in daily driver condition already (unless perhaps if it's a convertible). I'm not saying it has to be pretty. It just has to be driveable. If it's not, I wouldn't buy it!

Yes, my math is generalized, and certainly the older car is likely to need more repairs over the miles than the newer car. However, the older car is likely to be much easier to work on, thus making repairs less expensive as you can more likely do them yourself. Second, I think my overall point is still valid. Whether it's 33,000 miles or 66,000 miles or something else, it's likely to be many miles of driving before the extra cost for the gasoline for the older car finally catches up with the initial cost of the newer, higher mpg car.