Msd+k&n=gas Mileage

DAVID GAGNARD · #1 (**permalink**) 03-30-2003, 04:43 PM

Here's the story;In September of 2002 went to a car show,375 mile round trip,90% interstate driving,averaged 20.3 mpg for trip...

Last weekend,went to Pensacola for show,675 mile round trip,90% interstate driving and about the same outside air temp as Sept. show,averaged 23.5 mpg!!!!!!!!!!!!!!!!!!!!

About a month after the Sept. drive,something broke in my stock Duraspark distributor and I replace it with an MSD vacum operated unit.....Also for this trip I put my 3"by14" K & N air filter back on. Had it off and was using a paper filter for the original look at the car show,put the paper filter in the trunk and changed out at the show. The only other change on my car was I changed the engine oil and filter before the trip last week cause it was due anyway,Also this trip I carried a bunch more weight to boot.. Had a 13 year old boy ride along and the trunk was filled with boxes of parts to sell at the swap meet (did not sell,brought back home) as well as clothes and an ice chest in the back seat for the weekend... All in all this trip I'd say I had at least 300 pounds or more weight in the car than the first trip.....

I have noticed since changing the distibutor the motor has run "smoother" thru out the rpm range,as far as performance goes,you can not really tell by seat of the pants,but gas mileage DOES NOT lie. The only changes were the air filter and distributor,so thay must have worked ....I'll take 3.2 mpg increase any day and was very surprised to get it....Oh, forgot,paid anywhere from $1.70 to $1.98 for premium gas on the trip and at $1.98 I'll take a few mpg increase any day.......

Anyone else have any similar stories to share???????

David

RallySnake · #2 (**permalink**) 03-31-2003, 04:03 PM

David,

That's great mileage, you must be a smooth driver.

I have been using a MSD 6A for years and recently installed a new MSD vacuum advance distributor and Holley street avenger 670. With the new carburetor, I could fit a K&N 4 inch high by 14 inch round airfilter and an X-Stream filter top on it. It makes great power but I didn't know about the mileage.

When my son, David, and I drove to Texas and back, one of his responsibilites was keeping track of gas mileage. He didn't like this at first, the math was boring. But, when he found that he was getting better mileage than me, he liked it!

David just got his learner's permit and I made sure he kept the 400 horses under control. He regularly got 20 mpg using the Tremec's fifth gear and the Jag rear's 3.31 ratio, while cruising at the speed limit.

While I was driving through remote areas at more than three digits, the mileage dropped dramatically. On one long desert run, I almost ran out of gas. Fortunately, a station came up in time and even though it was closed, the pump let me fill up with a credit card. David was laughing when he told me I only got 14 mpg!

Paul

DAVID GAGNARD · #3 (**permalink**) 03-31-2003, 05:46 PM

Paul;

Not really a smooth driver,but on this trip we were four vehicles in our caravan....First off was a 2000 Ford F-250 diesel pullng a 24' enclosed trailer with a 70 Mach I in it.... Could only get it up to 65 or so in drive as the motor was taching around 2,800 rpms and redlines at 3000....Right behind him was a Suburban towing a 16 tandem open trailer with a 2003 Mach I,behind him was a 2000 Ford F-150,then here I came bringing up the rear,they kidded me about my gas mileage as the F-150 got about 20 mpg,the suburban got about 14mpg and the diesel only got 9 mpg,they said I was cheating and DRAFTING on the three vehicles in front.... I offered to take the lead,but they all knew I would put it on 75 or so and leave them,so they had me out back "watching the back door".

I promised them next trip would be different cause I was going to take the lead and leave the whole gang,hell they know the way better than I do anyway.....

I'm running a Tremec and a 3.00 rear gear in a 9",26" tall tires(I think)...

Highway mileage was great,this week I rode around town a lot and ran errands in the Mustang,I'm glad I did not check the gas mileage cause I know it was terrible.... For some reason it is poor in "city" driving ,but real good on the open highway.... A bigger difference than in most cars, maybe too many stoplights here....

David

Tinker51 · #4 (**permalink**) 04-01-2003, 12:06 AM

Tall rear gear + tall tires = bad milage in stop and go around town type driving. It works great for long highway trips as you noted.

DAVID GAGNARD · #5 (**permalink**) 04-01-2003, 11:42 AM

For some unkown to me reason,as long as I keep my cruising rpms at or under 2,000rpms my car gets real good gas mileage,over 2,000 it starts to drop a lot.....May just be my motor combo.....The motor does not have a wild cam,it does have a real good set of C9 iron heads and good valves and springs, a lot of low end grunt and good top end to 5500rpms.....It idles all day at 180 degrees at 800rpms and runs very smooth.... Very pleased with it since 99% of my driving is on the street and most of that is on the highway.....

David

rdorman · #6 (**permalink**) 04-01-2003, 12:44 PM

At 80 miles per hour my car is turning 3900 RPM. At that speed I average 15.5 MPG! Logged mileage and gas usage for 2000 mile and that was the figure!
Rick

Oh around town. About 3 BPG(blocks per gallon)

Heavy foot you see..........

DAVID GAGNARD · #7 (**permalink**) 04-01-2003, 01:43 PM

Rdorman;

That is really good gas mileage considering the rpms your turning....I'm turning 2000 rpms in 5th (tremec) and the needle is right at 75 mph. That's usually what I run on the interstate... I'm kinda like you in town driving,too many stop lights and too many people saying "let's see what she'll do"

I like to drive my car a lot and use it for work usually once a week..... Average about 18 mpg at work and use about 15 gallons a day at work @ $1.80 per gallon for premium,that's about $27.00 a day,on the other hand I use about 8 gallons @ $1.40 a gallon for regular in my company car,that's about 11 bucks a day....So gas mileage is important to me and I was very surprised at the gain when I switched to the MSD ditributor and K & N filter.... I really think the distibutor helped out more than the filter as I have noticed my car runs a lot smoother thru the rpms and my plugs look a lot better.....

David

rdorman · #8 (**permalink**) 04-01-2003, 01:55 PM

I was pleasently surprised at that mileage. There where several stretches where we averaged 80 and the mileage worked out to be 15.5. My next set of tires will be taller and will reduce RPM at 80 by about 300. I am adding a MSD unit to my Unilite distributor as soon as I get the new carb sorted out. I will be anxious to see if there is a difference.

Well time to go play with the car!

Rick