I have a 1974 VW Super Beetle that requires the highest - 91 - octane gas. What gas mileage should I expect?

Question

I had the engine rebuilt a few months after buying it, and I just had the body mostly restored and a fresh coat of light blue paint over it. I keep it tuned up, was advised to change the oil when the oil gets dark black [not necessarily waiting for the 3000 mile mark]. My mechanic says the carburetor needs a rebuild. I want to re-upholster the seats in my family's hunting tartan. Any advise about anything to improve her is appreciated.

Answer 1

Best Answer - Chosen by Asker

You had the engine redone- were the heads fly-cut or did the engine get any other modifications increasing its compression? 'Cuz that's the only thing that will make you use 91 octane. Other than that, 87's fine. Get that carb cleaned, rebuilt and properly set and you can expect about 25 mpg or so if you keep your foot out of it. Maximize your mileage by keeping proper tire pressure, and keeping the engine in tune.
Also, make sure all the cooling tin, thermostat and engine seals are intact.
Improvements?
1- Make sure you have good fuel hoses- and a fire extinguisher in the car. I've lost a Bug to an engine fire that started small from a broken hose and it's a heart-breaker cuz all you can do is stand back and watch the fire grow instead of putting it out 1, 2, 3.
2- PerLux Ignitor electronic ignition- no more setting points! Set this baby up once and forget it.
3- Full-Flow oil system- so you can use an oil filter! Again, make sure you have good hoses!
4- Header exhaust with a quiet muffler- unless you like the glass-pack sound. But they get louder with age... And while we're talking about exhausts, make sure you've got GOOD heater boxes, no exhaust leaks and that all the linkages work smoothly
4- Gages- Not required but good to have. A tach, Oil Pressure & Temperature, perhaps a cylinder head temp gage, too.
5- Sound system- of course you have to have your tunes! Just make sure that none of your hardware is visible! That package tray can hold a nice sub-box! And you can cover it up with either a custom dummy speaker tray (I put a pair of cheapo 6 x 9's on mine) or a store bought tray.
6- A good alarm to protect your investment!

Good Luck with your 74 Super! They're great little cars!

Source(s):

Personal experience- owned a 74 Super street custom.

Asker's Rating:

Asker's Comment:

Thorough answer and at the same time a bit overwhelming for a newbie like me. Sounds like I'll have to make a checklist ... BTW, a friend just pointed out that inside the little door to the gas cap it is written "OKTAN MIN 91 RON." The German manufacturers, even in 1973, indicate 91 octane.

Answer 2

assuming you get all the running issues in order, it seems i remember vw advertising them to get around 25 mpg.

Answer 3

Why would a super beetle vintage '74 need premium unleaded? Its not a high-performance car, therefore you can get by with 87.

Answer 4

Don't waste your money on 91. Use the 87. Your car doesn't require 91. Never has & never will. As far as mileage goes... With a good tune up & a good carb. 25-26 MPG. The oil will turn black about five minutes after you change it in the bugs. If you read up on your car you will find that the oil should be changed every 2000 miles. They don't have oil filters. Just a screen to stop the big chunks. They also need the valves adjusted almost every time you change the oil.

Source(s):

Bug owner & long time VW Tech

Answer 5

it should be pretty good u could put in 87 octane it wouldnt do anything but if a mechanic said your carb. has to be rebuilt then youll probily lose more miles per gallon