What gas mileage do you get on freeway?

[GolfingDuo]

In a stock Park Avenue, you aren't getting that kind of mileage without Tuning, fueling, hypermiling, and massive weight reduction. Period.

He goes downhill with a tail wind all the time. He also extends the 15 foot Tri sail and side fins.

😱

 

[Cadillac_AL]

At 34 or 35 mpg you could easily go 500 miles on a tank of fuel. Try that sometime and let us know how many gallons it takes. I always go 400-420 miles with no worries when I'm on the highway.

 

[pbrktrt]

The Series 1 was the low end torque and mileage king. The Series II has the higher RPM performance but a little worse mileage. But the mods are endless for the Series II and almost nil for the Series 1. I love em both for what they are.

 

[Kevandkaye]

fill the tank until it clicks off. don't put in any more. drive it until it needs gas, fill the tank until it clicks off. divide the gallons you needed to fill until it clicked off into the miles you drove. I still do it that way to keep the digital gauge in check...

 

[dmcelhannon]

My stepfather and mom did a trip from McAllen TX to OK City, OK. Out on the highways, they averaged 36 to 38-mpg. In town, they only got 12 to 14-mpg.

 

[cb3]

My stepfather and mom did a trip from McAllen TX to OK City, OK. Out on the highways, they averaged 36 to 38-mpg. In town, they only got 12 to 14-mpg.

There you go. It is possible and I'm not the only one. A local friend of mine claims 35 mpg freeway mileage. I claim 35 mpg also. Though we all both running KN air filters and keep our engines well tuned. I use Autolite plugs - nothing special. I think he uses some type of high snoot NGK plugs.

I admit that I do need to do a manual gas mileage check to verify the accuracy of my gas mileage meter, but the gas does seem to last a very long time, and it does seem plausibly possible to me that my fuel economy meter might be correct.

 

[cb3]

The Series 1 was the low end torque and mileage king. The Series II has the higher RPM performance but a little worse mileage. But the mods are endless for the Series II and almost nil for the Series 1. I love em both for what they are.

I thought Series II has more torque, hp, and gas mileage than Series I.

My dad has a Series I in a 1994 Olds 98 (which is same size car) and it's got noticeably less torque from a dead stop, and less hp when wound up. Noticeably less powerful at all rpm.

So I always thought Series I has less torque and hp, but maybe it's just his Series I engine? (He doesn't maintain his Series I as well as I maintain my Series II, though his seems to run OK.)

Also, Wikpedia said Series II is higher performance, but only mentioned better horsepower and gas mileage. No mention of torque of Series I.

===

What is the rated horse power of a well maintained Series I vs Series II? I'd like to compare because I want to buy an Olds 98 and have a choice of engines (depending on model year).

 

[Cadillac_AL]

I'd still like to see one of these cars go 500 miles without a fill up.

 

[Drakito]

On a recent 850 mile road trip we averaged 30mpg on the freeway with the Ultra. Cruise was set at 80mph. Around town with lots of stop and go driving, around 16-18mpg. 91 octane always. I found we got lower gas mileage at 65mph than at 80mph. (Speed limit for more than 400 miles of the trip was 80mph).

The road trip was from the Southwest of Utah to the Northeast. Only had too fill up twice. Once for the drive up, once for the drive down. Altitude started at 1800ft then went up to over 6900, then back to around 5000 for most of the trip up. I still had 1/4 tank at the ends of both legs. Less than 15 gallons used for each leg. (Not total)

 

[cb3]

A 100 mile drive is not a good test for gas mileage unless you filled the tank at the same location, same pump, same position of car & same full tank level. Drive for another 250 miles and fill it at the same location, same pump, same position of car & same tank level when filled.

I did all those things you mentioned above. It's years later now. It still averages 33-34 mpg driving 70 mph on highway.

 

[cb3]

I guess I'm lucky.

My Park Ave gets very good gas mileage. Seemingly impossibly good gas mileage.

It also has no mechanical problems of any kind. Seems to be the perfect car.

Note: A friend of mine has some other type full size GM car with same Buick 3.8 Series 2 engine and he says he gets 35 mpg highway. I don't remember the model of his car.

I don't know if my mpg meter is accurate, but a tank of gas lasts a long time.

My car does have a KN air filter, fresh tune up, and 195 thermostat. Perhaps those things help?

I later switched from K&N air filter to Wix or Baldwin paper filters. Still averaging 33-34 on highway trips. So the air filter isn't a factor.

 

[DrivenDaily]

I later switched from K&N air filter to Wix or Baldwin paper filters. Still averaging 33-34 on highway trips. So the air filter isn't a factor.

What most folks don't take into account is that the "high performance" air filters tend to be made more for very high RPMs. They also allow larger particles to enter the engine, which are "just the right size" to grind the innards of the engine more aggressively than the smaller particles that make it past the paper filters.

At freeway speeds, the engine is turning around 18oo RPM. Since it's a 4-stroke, only half of the engine is consuming air on each revolution. A gallon (4 quarts) is 3.785 liters, and remarkably the "3800" engine is about the same size, so that means that it consumes only half a gallon per revolution. I don't know how many gallons are in 1 cubic foot, but a lot of volume measurements use CFM as the unit. For the sake of us regular Joes, a gallon is more familiar.

At 18oo RPM, only about half a gallon is consumed per revolution. 18oo RPM (times) ½ gallon = 9oo gallons per minute. Divide that by 60 and you get 15 gallons per second (GPS).

At higher RPMs, it consumes more air, so 36oo RPM = 30 GPS or 18oo GPM. 54oo RPM = 45 and 27oo. And if you're spinning the guts of out it at 72oo, those are 60 and 36oo.

The ECM tries to keep the air-fuel mixture as close to a stoichiometric ratio of 14.7 PPM (parts per million), which means that for every 1 million gallons of air consumed, it'll need approximately 14.7 gallons of fuel.

If the paper air filter is more than capable of passing enough air at any RPM, then a higher-flowing filter really isn't needed, even for boosted applications. And no one in their right mind would use sand paper on the cylinder walls, pistons, and rings. There is more power to be gained from other power adders than from that kind of air filter.

All of the above is my opinion. YMMV

 

[cb3]

What most folks don't take into account is that the "high performance" air filters tend to be made more for very high RPMs. They also allow larger particles to enter the engine, which are "just the right size" to grind the innards of the engine more aggressively than the smaller particles that make it past the paper filters.

At freeway speeds, the engine is turning around 18oo RPM. Since it's a 4-stroke, only half of the engine is consuming air on each revolution. A gallon (4 quarts) is 3.785 liters, and remarkably the "3800" engine is about the same size, so that means that it consumes only half a gallon per revolution. I don't know how many gallons are in 1 cubic foot, but a lot of volume measurements use CFM as the unit. For the sake of us regular Joes, a gallon is more familiar.

At 18oo RPM, only about half a gallon is consumed per revolution. 18oo RPM (times) ½ gallon = 9oo gallons per minute. Divide that by 60 and you get 15 gallons per second (GPS).

At higher RPMs, it consumes more air, so 36oo RPM = 30 GPS or 18oo GPM. 54oo RPM = 45 and 27oo. And if you're spinning the guts of out it at 72oo, those are 60 and 36oo.

The ECM tries to keep the air-fuel mixture as close to a stoichiometric ratio of 14.7 PPM (parts per million), which means that for every 1 million gallons of air consumed, it'll need approximately 14.7 gallons of fuel.

If the paper air filter is more than capable of passing enough air at any RPM, then a higher-flowing filter really isn't needed, even for boosted applications. And no one in their right mind would use sand paper on the cylinder walls, pistons, and rings. There is more power to be gained from other power adders than from that kind of air filter.

All of the above is my opinion. YMMV

I agree!

I came to same conclusion as you state above after realizing that the K&N air filter on my Jeep was letting in fine talc powder type dust. I had driven in dry sand at a beach. Local beaches in my area have fine, powdery volcanic ash dust mixed into sand. The inside of air intake tube was coated with visible dust! Groan. I immediately changed my Jeep's motor oil and installed a Baldwin paper filter.

I then did same with my Buick.

Paper filters are cheaper and better, if you buy a quality brand such as Baldwin, Wix, AC Delco, Napa, etc.

 

[cb3]

I'm still averaging 33-34 mpg at 70 on highway trips in my 97 Park Ave naturally aspirated car with 105K miles on odometer. I'll tell specifics about my car below. I think the details below combine to give me good gas mileage.

My 3800 is naturally aspirated, well tuned, has 3 new NAPA Premium coils and plug wires. Plugs are Autolite Single Platinum with 55K miles on them, Hankook all season tires (30 psi front, 27 psi rear). It runs smooth and power is good.

I'm using Valvoline Maxlife Synthetic High Mileage Blend 5w30 (silver jug). It starts easy on colds days and flows easily at full op temp. It's efficient, IMO. However, I have a slight drip. So next time I'll use Maxlife 5w30 Synthetic Blend in hopes of reducing drip.

I have a 195 Stant thermostat which works great because it keeps a good steady op temp, which I think helps efficiency. I briefly tried another brand (forgot which) that let temp continuously cycle up and down, which was not good for efficiency.

I use mid grade gas 89 octane tier one gas because it seems to run smoothest and have most power and gas mileage with 89 octane. I tried 87 & 91 octane gas and my motor doesn't run as well with those. My engine is naturally aspirated.

My Hankook All Season tires are the best tires I've ever owned. They're quiet, smooth riding, have good handling and traction, and are fuel efficient. 30 psi front, 27 psi rear.

My car has newish front struts (shocks and springs). Rear spings and air shocks are also newish. All those things were replaced around 55K miles). The rear supsension is adjusted to give car a 1 inch positive rake. Positive rake increases aerodynamic efficiency because more air flows over car and less air under car.

My car is well tuned.

I did similar things for my 99 Jeep Cherokee XJ (except different tires of course, and for Jeep a 205F Stant thermostat because Jeep 4L like to run at 205-215F). My Jeep gas mileage improved from 16 to 23 mpg at 60 mph.

My Buick PA gets 33-34 mpg at 70 mph. I don't drive like a hypermiler. I just drive like an old person not in a hurry, put on cruise at 69 or 70 mph and then don't worry about it.

Gas mileage drops to 30 mpg if I drive slightly above 70 mph. If I drive above 74 mph then gas mileage is terrible (around 25 mpg). So I drive 70 mph.

 

[Rich B.]

Envista is 42MPG so far on day trips. Around town down to 28 and dropping. But this is a 3 cylinder lmao.

 

[Rich B.]

What most folks don't take into account is that the "high performance" air filters tend to be made more for very high RPMs. They also allow larger particles to enter the engine, which are "just the right size" to grind the innards of the engine more aggressively than the smaller particles that make it past the paper filters.

At freeway speeds, the engine is turning around 18oo RPM. Since it's a 4-stroke, only half of the engine is consuming air on each revolution. A gallon (4 quarts) is 3.785 liters, and remarkably the "3800" engine is about the same size, so that means that it consumes only half a gallon per revolution. I don't know how many gallons are in 1 cubic foot, but a lot of volume measurements use CFM as the unit. For the sake of us regular Joes, a gallon is more familiar.

At 18oo RPM, only about half a gallon is consumed per revolution. 18oo RPM (times) ½ gallon = 9oo gallons per minute. Divide that by 60 and you get 15 gallons per second (GPS).

At higher RPMs, it consumes more air, so 36oo RPM = 30 GPS or 18oo GPM. 54oo RPM = 45 and 27oo. And if you're spinning the guts of out it at 72oo, those are 60 and 36oo.

The ECM tries to keep the air-fuel mixture as close to a stoichiometric ratio of 14.7 PPM (parts per million), which means that for every 1 million gallons of air consumed, it'll need approximately 14.7 gallons of fuel.

If the paper air filter is more than capable of passing enough air at any RPM, then a higher-flowing filter really isn't needed, even for boosted applications. And no one in their right mind would use sand paper on the cylinder walls, pistons, and rings. There is more power to be gained from other power adders than from that kind of air filter.

All of the above is my opinion. YMMV

Think gallon is equal to .14 CF rounded out. Interesting theory about filters, could very well be right. Wonder if any contaminants would be burned up w/fuel before absorbed by oil? Know you can burn water (water injection) with fuel and will prevent low octane pre-detonation so that’s further advance of timing.

Have another car that has factory K&N with Track Key (Boss 302). Those are supposed to be sprayed with oil prior to install… you could still be correct, Ford does not have all the best answers or choices.

 

[abe froman]

In a stock Park Avenue, you aren't getting that kind of mileage without Tuning, fueling, hypermiling, and massive weight reduction. Period.

This is not true At All!
I just bought a 2002 PA 95k miles, garage kept.
On the ride home from buying it I averaged 34mph highway(Chicago, winter gas blend)
I have had the PA for 20 fill ups now and I will get between 32-34 highway and 19-21 city. I expect it to go up 1-2 mpg after I optimize the psi and engine maintenance.
I calculated just about every tank of gas in the past 6 cars I've owned religiously.

 

[Rich B.]

Not doubting any findings whatsoever, doesn’t really matter. Cruise control is gas saver (constant light pedal detention), it’s how much you normally press and let up on pedal. “0” vacuum or 5/1 air/fuel ratio is not a mileageminder. Both ways are telling you exactly same thing, different resources and derived at a bit different.

 

[Pirate Pete]

This is not true At All!
I just bought a 2002 PA 95k miles, garage kept.
On the ride home from buying it I averaged 34mph highway(Chicago, winter gas blend)
I have had the PA for 20 fill ups now and I will get between 32-34 highway and 19-21 city. I expect it to go up 1-2 mpg after I optimize the psi and engine maintenance.
I calculated just about every tank of gas in the past 6 cars I've owned religiously.

I was just on the highway a few hours ago. I averaged between 30 - 35mpg on a flat freeway with cruise control set at 68mph

 

[cb3]

My car does have a KN air filter, fresh tune up, and 195 thermostat. Perhaps those things help?

I switched to a NAPA Gold paper air filter. Still same gas mileage as I got with K&N air filter. The paper filter does a better job of filtering out dust.