General Rant!

[8NFord]

Greetings,
Just returned from the local filem up store, with gasoline prices still over $2.00 here in north Alabama.
Why am I on this you may ask? I am driving a 1973 MG-B that has SOME mods like the Weber 32/26 carb, Peco 2 inch exhaust, standard ignition other than the coil which is high output. The transmission is a standard 4 speed with NO overdrive. What does all this mean you may also ask? It means that I have a car over 30 years old that I can drive on the interstate and get over 40 mpg!
Why is it that current cars with all the so called electronic improvements are just now beginning to approach this point? One would think that with the overdrives, electronic ignition, fuel injection, computer controls we would be receiving 80-90 mpg at this point of development. Yes, and I do understand that cars are 'heavier", and have air conditioning, and power steering, but some cars do not and 30 years have now come and gone with no change other than fuel is now over $2.00 a gallon instead of 50 cents a gallon. In 1960 when I began driving in southern California the highway 99 gas price wars would bring fuel costs down to 5 gallons for a dollar, but that is another completly different rant!
/ubbthreads/images/graemlins/rolleyes.gif

 

[Matthew E. Herd]

Frankly, 40 MPG is awesome! I know you mentioned weight, but I see that and displacement as the two primary limiting factors. Also, lately the power to weight of street cars has been dramatically improved at the expense of mileage. However, its hard to say why there hasn't been more emphasis on mileage ... David Vizard mentions a Mini he tuned to make over 50 mpg at 55 mph in his book, tuning the A series engine! Clearly, it can be done, its just a matter of cost effectiveness (much more now that gas is 2.00+ a gallon in stead of 1.35 or 1.50).

All in all, it would make a fantastic engineering project, but making a totally optimized fuel economical car would probably cost more than they consider it worth /ubbthreads/images/graemlins/smile.gif An MGB would be a good starting point though, if anyone wants to finance it, I'd be willing to work on it /ubbthreads/images/graemlins/wink.gif

 

[8NFord]

I intend to install the pertronix "Ignitor II" ignition system within the next few weeks. I am not sure as to what change that will present, if any.

However, I do expect a slight gain when I do the 5 speed swap. I have been holding off on that while I made up my mind about 5 speed vs overdrive, but I have decided that the 5 speed will be a little less of a problem than the overdrive. As the drive ratio will drop from a 1:1 to a .80:1, I am hoping to gain another 4-5 mpg on longer interstate cruises.

I have not heavily tuned the car, just performed the expected maintenance. The engine was completely rebuilt (I have ~$3,000.00 in invoices from last owner) around 700-1000 miles ago. In all fairness, it did not run worth anything when I picked it up. After some new points and plug wires, adjusting tappets & timing, & a new exhaust system along with other routine stuff it came to life.

I have made several 250 - 450 mile trips with carefull record keeping on fuel purchases. At present the car is my daily driver to work.

/ubbthreads/images/graemlins/computer.gif

 

[78Z]

I believe in lowering emissions fuel economy drops off a bit. I know all my 70s R&T magazines they mention the fuel economy drop. Not sure exactly why but maybe a richer mixture is needed for the catalyst?

 

[GavinR]

It's more an issue with engine capacity in North America. Also as has been mentioned most cars weight at least 50% more than an MGB even the smaller ones. In the UK where gas is around $5 a gallon the cars are a darned sight more efficient. They also have a lot of diesels over there which are cleaner running than gasoline engines. Before we moved over here my wife had a Peugeot 306 TDi which would do 0-60 in around 7.5 seconds and still return 65 mpg all day long. It was a bit of a shock coming over here as (apart from the Jap stuff) all the North American vehicles are 10-15 years behind the European stuff in terms of design. Many of the V engines are still using OHV for heavens sake. I can't recall anything being built with this type of engine over there for maybe 20 years.

It's actually a good job for the North American auto industry that not more of the European motor manufacturers bring over their cars as the industry here would be wiped out. It doesn't seem to be able to change. Take for example the Subaru WRX, being hailed here as amazing, well I hate to tell you but I had one in 1992 and it was a couple of years old then! I could go on about N American manufacturers not making the cars people want to buy but I've got a car to build!

GavinR /ubbthreads/images/graemlins/england.gif /ubbthreads/images/graemlins/canpatriot.GIF

 

[Matthew E. Herd]

Well 8N, I think you've initiated a very successful (and interesting) rant! /ubbthreads/images/graemlins/smile.gif

 

[aerog]

[ QUOTE ]

It means that I have a car over 30 years old that I can drive on the interstate and get over 40 mpg!

[/ QUOTE ]

Add a 5-speed or OD and maybe you'll see 45-50! /ubbthreads/images/graemlins/shocked.gif

I have to admit this is the first time I've heard anyone rave about getting that kind of efficiency; when they were new they averaged in the 20mpg-range (high 20s to 30-31 highway). My twin-HIF '77 w/OD will get 28-ish on the highway, but that kind of driving is rare for me.

 

[Ed Bell]

We just make a 600 mile weekend trip last month, and averaged 29.7 miles per gallon. (1962 MGA) The only problem was that while on the interstate I kept reaching for another gear! I'm leaning towards a 5 speed conversion, but the cost holds me back. We don't travel the interstate that much, but in Washington the speed limit is 70 MPH, and I don't like to hold anyone up. For now, I look for two lane roads whenever possable.

 

[Bruce74B]

I'm not sure how you guys are getting that kind of milage from you cars, but my 74 B gets 20-25 combined driving...granted, I run it hard some (OK, maybe most) of the time. But I also get 25.8 MPG with my Chrysler LHS when combined with mostly highway driving in a lot more comfort. But it isn't nearly as fun to drive /ubbthreads/images/graemlins/driving.gif

Bruce /ubbthreads/images/graemlins/cheers.gif

 

[8NFord]

I drove the MG-B to and from work for about one to two months before going out on the I-65 interstate. I have always watched my MPG on the cars. My 73 Triumph Stag only runs about 25, but I have never really attempted any longer trips in it. Perhaps it is time.

As to the MG-B's mpg, I can not really explain it. I live in Madison, AL which is just off US I-65 hwy. On my first real trip out, I drove south to Birmingham (~100 miles) and about 40 miles east before stopping to check things over. I expected to be down about 6 or 7 gallons, but it only took 3.2 as I recall to fill the tank back up. I drove on over to the Road Atlanta (GA.) race track for the weekend and filled up outside the gate. I drove around there, and made about 15 laps on the track. I refilled at the same station upon leaving the track, and did not refill until arriving back at Madison. The trip back was via the US I-75 north to Chattanoga, TN and on west to Madison, AL.

As to my driving habits, I drove rather cautious (60 mph) on the trip as I was not really sure how the "B" would travel on the interstate. After the suprise at the first fillup, I decided to continue at the same speed just to see if the mpg was a fluke or just what. As it happened, it stayed the same. I fill up the tank until such point that I can see the fuel sort of splash back up in the filler neck each time and quit at that point.

As I said, as far as I know, the car is standard other than the Weber 2bbl, Peco header, Flowmaster muffler, and high output coil. It currently still has standard points, no solid state ignition yet. If the average consensus is 25 mpg on the hwy, I really don't know what to say other than I have been cautious on monitoring putting in fuel and how much is used.

One thought is that I have been running the higher octane lately as (about 2 months ago) I filled up one time at the local Wal-Mart with the lowest grade and couldn't hardly make it home. I am not sure what effect this would be, if any other than another 20 cents per gallon.