Gulf Coast Filters Specializing in Bypass Oil filters, Fuel filters, Hydraulic filters and Custom filtering



Gulf Coast Filters

About Us 
Customer Comments
Meet Some Of Our Customers
Frequently Asked Questions
Why do we change oil
How do I eliminate routine oil changes
Why Bypass Filters
Our Guarantee
Contact us
Filter Installation
GCF Element Change Instructions

Oil Analysis

GCF Oil Analysis program

The Oil Quality



1,000,000 Miles We Did It
Power Stroke Registry Review
North Carolina D.O.T
Turbo Diesel Registry Magazine

GCF Customers

Pepsi Cola Letter
Satisfied Users
Other Letters

Test Results

GCF vs. small competitor filter
Offshore Drilling
Scott Paper Co.

Gulf Coast Filters
High Quality Filters
for Over 30 Years!



Bypass Oil Filter
By Lewis Haehl

Just about everyone is aware of the importance of changing their oil these days. You would have to be deaf, blind, or live under a very large rock to not notice all of the advertisements on televisions and in print for oil-change establishments.

The PSR has been active in pointing out the many benefits of changing engine oil, especially on a Power Stroke Diesel. Changing your engine’s oil is probably the single most important thing you can do to promote longevity and driveability from your Power Stroke. 

Modern oil filters are very efficient and recent technologies and new filtration media have advanced oil filtration. Clogging is probably not very common, but remember you often get what you pay for. Do you want to protect your $10,000.00 engine with a $5.00 filter? Maybe a more expensive OEM (Original Equipment Manufacturer) filter from Motorcraft or International would be a wiser use of your money?

Using quality oil and filters at or before the recommended service interval should be one of the primary goals of every owner. But, what if I want to do more? For those who want to go the extra mile there is always something more you can do or add to go to the next level. One way to do that is, when it comes to oil maintenance, is to add a bypass oil filter to your lubrication system. One such device is offered by long-time PSR advertiser, Gulf Coast Filters of Oklahoma.

The premise behind a bypass filter is implied by its name. “Bypass” some of the oil from the main oil galleries and send it to the bypass filter for micron-filtration. The bypass filter takes a very small amount of oil at low pressures, allowing the main filter and the rest of the lubrication system to do their jobs. 

If you have ever noticed, regular oil filters are referred to as “ full-flow” oil filters. This means that these oil filters have the ability to handle the full volume of your engine’s lubrication system. Your engine’s oil filter has to filter all of your oil at a fast flow rate, so there is always enough oil in the oil pan to the system. The International Power Stroke Diesel has a particularly high-volume oil pump. These pumps circulate the entire 15-quart sump capacity through the engine about once every ten seconds. That oil is moving very fast.

Using OEM filters and premium oil to feed your mechanical baby will satisfy your warranty requirements and probably make your Power Stroke last longer than most of us will keep our trucks. But, there are those that want to do everything they can to preserve and protect their engine and are possibly looking towards one-million miles as a goal. If this sounds like you, then a bypass filter from Gulf Coast Filters may be a product you need.

Bypassing The System

Regular oil filters do have a “bypass” feature of their own, but this is not a good bypass, it’s a bad bypass. If your engine’s oil filter becomes clogged, the engine still needs to be fed oil, whether that oil is filtered or not. If your filter goes into bypass mode the engine oil will not be filtered, and the oil will continue to circulate, unfiltered.

When not in bypass mode, your oil filter has to flow at such a high volume of oil that it can only filter particles down to a certain size, usually down to approximately 15 microns. This means that the particles that are smaller than 15 microns are allowed to pass through your engine unchecked. These little abrasives get into the smallest of places and accelerate wear.

Bypass filtration is not a new technology, nor it is uncommon. A partial list of Gulf Coast’s customers confirms that there are many who have a lot more invested in their machinery than we do, and they are using Gulf Coast Filters’ filtration technology. NASA, Shell Offshore, Inc., Marine Transportation Inc., Scott Paper Co., the U.S. Army National Guard of fourteen states, several U.S. Air Force bases, and the U.S. Army, U.S. Navy, U.S. Coast Guard all use Gulf Coast’s products.

Where The Wear Comes From

First of all, oil doesn’t really wear out, it just becomes contaminated, and additives become depleted. Many of these contaminants are caught by the factory oil filter, but those smaller than what the stock oil filter can catch are allowed to circulate through your engine. These contaminants are suspended in your engine’s detergent oil and are removed when you change your oil. But, what if you could prevent many of these contaminants from living in your engine oil? 

Gulf Coast Filters says that over 80% of the normal wear generated within an engine is attributed to the contamination that conventional oil filters miss. That is because 95% of the contamination generated within the engine is from contaminants that are 10 microns or smaller. These small particles can be very destructive.

Bypassing You In Slow Motion

To filter these small abrasives from engine oil, the rate of flow has to be reduced. Gulf Coast Filter’s Model O-1 Bypass Oil Filter cleans the bypassed oil at a rate of only one-half gallon of oil per minute. At this slow rate, the Gulf Coast bypass oil filter provides excellent control of particles from 1-10 microns. In addition, the filter removes moisture down to 40 parts-per-million (PPM), and it can extend your factory oil-filter-change interval up to five times.

Never Change Your Oil Again?

After installing their system, Gulf Coast is confident that their filtration will keep your oil so clean that you will never have to change your oil again! Of course, regular oil-analysis is an important part of any extended oil-drain procedure, and we often recommend oil analysis even if you don’t extend your oil change intervals. There is much information waiting to be discovered inside your used engine oil, but that is a separate topic that will have to wait for an upcoming issue of the PSR.

Gulf Coast recommends that you change your Gulf Coast Filter every 10,000 miles and your factory oil filter about every 25,000 miles! The Gulf Coast Model O-1 Filter adds approximately six quarts of oil to your Power Stroke lubrication system. This is a 40% increase in oil capacity for a fifteen-quart system on a 1999-up Power Stroke Diesel.

That means that your oil capacity is now twenty-one quarts, about 1.5 quarts more than the lube system of a T-444E in an International medium-duty truck. The regular oil change interval on a T-444E International equipped truck is 10,000 miles. Of course, they recommend you change all of that oil every 10,000 miles, but these are engines without bypass filtration.

Although Gulf Coast doesn’t call this filter change an oil change, the fact remains that when you replace their filter and add the make-up oil, 6-quarts, you are adding lots of fresh oil with this partial oil change. Forty percent of your original oil capacity of fifteen.

The Gulf Coast Filters bypass oil filter provides superior oil filtration with or without routine oil changes.

Where’s The Proof?

We admit that we are often skeptical and prefer for someone else to take the initial leap of faith and to prove a product. The literature we received from Gulf Coast Filters gave us such an example.

In 1990, 18-wheeler Owner-Operator Randy Rogers from Gallatin, Tennessee purchased a new Peterbilt tractor powered by a 425-HP Detroit Diesel engine. At 19,000 miles the break-in oil was drained. At 27,000 miles a Gulf Coast Filter's Model O-2 bypass Oil Filter was added to the engine; the oil was not changed at this time.

Every 10,000 miles the Gulf Coast bypass filter was changed and make-up oil was added (these big Diesels use many more GALLONS of oil than our little Power Strokes). Every 50,000 miles the three factory filters were changed. No routine oil changes were performed, just bypass filter changes and oil-level topping. At 250,649 miles, the oil pan developed a leak, and a Peterbilt dealership in Nashville, TN, replaced the pan gasket under warranty. During this repair the oil was drained and new oil was added.

At 500,000 miles the oil was drained for an engine inspection, which was attended by U.S. Air Force officials from Elgin AFB, Florida, and engineers from Shell Oil Company, and Don Culpepper, vice-president of sales and marketing for Gulf Coast Filters. This inspection consisted of rod and main bearings, the crankshaft, the cleanliness of the block, and inspection for cleanliness and the condition of the head. The results of this inspection were amazing.

The oil pan was very clean, and the oil pump didn’t show any signs of wear. The block was extremely clean. Main bearings 2-6 were removed and inspected, all were in excellent condition. Even the tin overlays were still intact, and a micrometer indicated there was no measurable wear on the bearings. The upper half of the rod bearings still had their tin overlays intact and showed only normal break-in wear. The 500,000-mile crankshaft looked new.

The valve cover was removed, and the mechanics doing the work were amazed. The mechanics indicated that the vent screen is normally full of sludge, and medium to heavy deposits on the inside of the valve cover are common on engines that have a Jake-Brake. The head on this engine was exceptionally clean to the point that one could read the writing on the Jake-Brake data plates.

The engine was put back together, and the used oil was put back in the engine. No parts were replaced! Fast-forward a few years and that same Diesel engine has now logged over one-million miles, with only two complete oil changes! Wow.

While the above test is not on a Power Stroke, it is on a heavy-duty Diesel engine, and provides a very nice example of the Gulf Coast bypass-filter’s capabilities. The simplicity of the design makes this a very interesting product. If you are checking into bypass filtration, the Gulf Coast Filter deserves a closer look. 

Gulf Coast Filters of Oklahoma
John R. Birdsell,



Home page / About us / Contact us

Copyright © 2002-2005 Gulf Coast Filters, Inc.  All Rights Reserved.
Gulf Coast Filters
P.O. Box 2787
Gulfport, MS  39505