OEM BMW E46 Steering Wheel options:

Below are the steering wheel options offered on all BMW E46 models throughout its production run from December 1997 through August 2006. Only two steering wheel sizes were available, 375mm and 385mm.

All steering wheel options were airbag equipped. The standard sport package steering wheels did not have the thicker grip or thumb rests found on the ZHP and M3 models. Alcantara wrapped wheels were reserved for the M3 CSL and ZHP and ZCP models. ZHP was the option code used for the high performance sport package on the US Spec 330i models. ZCP was the option code used for the Comeption Package equipped M3 models. ZSP was the option code used on the standard sport package for non M3 models.

BMW E46 reference quick links:

✔ Dirty steering wheel stitching? Learn how to renew steering wheel stitching back to new. HERE

✔ E46 wheel style options, specs: HERE

✔ E46 M3 wheel style options, specs: HERE

If you are able to offer a reliable source on any missing information below, please click the "CONTACT US" button on the bottom of this page.

Oversteer and understeer are two terms commonly used in the automotive world, especially when it comes to talking about performance. BMW models are known to be tail happy due to their rear wheel drive bias which creates oversteer. Below we will go over the differences and advantages of both performance characteristics.

What is understeer?

Understeer is simply the result of the vehicle turning less than expected from the driver’s input. Understeer typically causes the vehicle to slide off the road in a turn. The vehicle slides forward despite the steering wheel being turned. Understeer is more common in front-wheel drive vehicles. This is due to the front wheels having to deliver power, maintain direction, brake, and maintain traction. This is a lot to ask for compared to rear-wheel-drive vehicles. See image below for further clarification.

What causes understeer?

Understeer is most commonly caused by the driver entering a corner at too high of a speed for the vehicle’s setup. The front wheels lose grip, causing the vehicle to slide straight rather than turning direction. The solution to fixing the understeer is to enter the corner slower or to add more front grip to the vehicle to prevent sliding.

What is oversteer?

Oversteer is simply the result of the vehicle turning more than expected from the driver’s input, most commonly found in rear wheel drive vehicles. This typically causes the vehicle to spin out by the back end kicking forward. See image below for further clarification.

What causes oversteer?

Oversteering occurs when too much power is sent to the wheels than it can handle. Oversteering is typically undesirable, however, the controlling of a vehicle’s oversteer is commonly seen in power-sliding or drifting of cars. This controlled oversteer holds the at the threshold of grip while preventing the back end from completely spinning the vehicle around.

What are the advantages and disadvantages?

Understeer advantages:
➊ More stable than oversteer
➋ Less harsh on tires than oversteer
➌ Safer in the rain

Understeer disadvantages:
➊ The vehicle is less responsive than oversteer
➋ Slower turn-in speeds

Oversteer advantages:
➊ Faster turn-in speeds
➋ Faster cornering speeds than understeer

Oversteer disadvantages:
➊ More unstable than understeer
➋ Harsher on tires than understeer

Why is understeer and oversteer important?

Too much of either is not ideal. It is the difficult responsibility of automakers to fine-tune the performance of their vehicles to have the perfect combination of understeer and oversteer in various conditions to ensure driver safety. With the advances in modern electronics in vehicles, understeer and oversteer can be managed to safely drive vehicles around corners in all types of environments.

Most BMW drivers prefer slight oversteer, which is ideal for the classic rear-wheel drive setup. With the increasingly common all-wheel drive, X-Drive function of BMW models, oversteer is being corrected by adding front-wheel drive in combination with rear-wheel drive. Modern M cars equipped with M X-Drive are capable of disconnecting the front-wheel drive system leaving the rear wheels delivering all the power. This changes the driving dynamics of the vehicle at the press of a button and allows for more versatility in the driving characteristics of the vehicle. Normal road use typically engages the M X-Drive system for safety, while disengaging the front wheels on the track will provide for more playful (and more dangerous) handling characteristics.

Where can I learn more BMW fun facts?

Learn more BIMMERtips fun facts by clicking HERE

BMW F10 M5 wheel style numbers, specs:

Below are the wheel style options available for the F10 M5 for the world wide market. Only three options were available over the life of the F10 M5. All models were forged aluminum and factory equipped with runflat performance tires.

The BMW F10 M5 is BMW's fifth generation M5, manufactured from 2011 - 2016. The F10 M5 is BMW's first turbocharged M5 model. It is powered by a twin turbo, 4.4L V8 which outputs a maximum 553HP and 502lbft. 0 - 62mph takes just 4.4 seconds. Overall weight is 4,288lbs (1,945kg) which is a total of 198lbs (90kg) MORE than the outgoing E60 M5 V10 model.

The F10 M5 celebrated the 30th Anniversary of the M5 in 2015. As a result, BMW manufactured a total of 300 special edition models named "30 Jahre BMW M5". All vehicles were finished in Frozen Dark Silver Metallic Individual paint. Cosmetic upgrades were found throughout the inside and outside of the vehicle.

✔ Check out our BMW wheel style number guide HERE

✔ Learn the F10 M5 paint codes and color options HERE

OEM BMW E30 Steering Wheel options:

Below are the steering wheel options offered on all BMW E30 models throughout its production run from 1982 - 1994. Only one steering wheel design was used for airbag equipped models. The remaining five offerings were all non airbag equipped models. The Mtech 1 steering wheel was offered in two diameters, 370mm and 385mm. The 370mm wheel options is more rare, therefore more desirable.

It is important to note if you are switching from an airbag wheel to a non airbag wheel (or vise versa), the turn indicator and wiper stalks are different. The airbag steering wheels sit further away from the stalk mounting points, thus have a different bend in the stalks to bring the stalks closer to the wheel. If you want to swap steering wheels from airbag to non, ensure to switch the stalks that match the wheel type to ensure proper offset distance. A non airbag wheel with airbag stalks will be closer and your hand will likely interfere with the stalks when turning the steering wheel.

BMW E30 reference quick links:

✔ Learn how to remove a non airbag BMW steering wheel HERE

✔ Sloppy BMW E30 steering feel? Learn the 5 minute fix HERE

✔ Replace your worn, lost Mtech 1 steering wheel badge HERE

✔ Make sure to check out our entire E30 quick reference guide on tips and tricks HERE

If you are able to offer a reliable source on any missing information below, please click the "CONTACT US" button on the bottom of this page.

What is an engine water pump?

A “water pump” is part of the coolant system of a vehicle that moves coolant through your engine block, radiator, and hoses to extract heat from the engine through convection. All BMW motors are water-cooled. This compares to other engine types like older Porsche and VW engines which are air-cooled and do not require any coolant.

What does water-cooled mean?

The term “water-cooled” does not translate literally to just plain water, however. The coolant system in your BMW uses typically a 50/50 mixture of water mixed with coolant/antifreeze. Coolant/antifreeze contains a chemical called Ethylene glycol, this chemical additive allows the coolant mixture to freeze at extremely low temperatures and boil at extremely high temperatures. These properties are perfect for vehicles in cold climates where you do not want the coolant to freeze inside your engine block. Freezing water expands and can crack your engine block if not mixed properly with coolant/antifreeze. Furthermore, as your engine operates it generates heat. The proper mixture of coolant will prevent the coolant system from boiling, allowing a higher coolant temperature.

What happens if my engine overheats?

Overheating of your engine can cause catastrophic damage. The extreme heat can warp your vehicle’s cylinder head, crack your engine block, create a leaky head gasket, and more. Under no circumstance do you want your vehicle to overheat. Avoid overheating at all costs by paying attention to your engine temperature gauge and pulling over on the side of the road if high temperatures are approaching.

How does a water pump work?

A water pump consists of impeller blades that rotate typically off of an accessory belt that runs off the crankshaft pulley. Modern BMWs use electronically driven water pumps to free up engine power and increase efficiency. The water pump impellers rotate and cycle the coolant through the coolant system. The cool coolant passes through the engine block, extracts the heat from the engine block through conduction then transfers to the radiator. The coolant passes through the radiator while air passes over it, reducing the temperature of the coolant in the process. Then, the cycle repeats.

Why do BMW water pumps fail?

Like all wearable parts, over time they fail. Water pumps are not intended to last the life of the vehicle, no matter who the carmaker is. The typical point of failure for the mechanical (belt-driven) water pumps is either the bearings or the plastic blades. The OEM BMW impellers consist of plastic blades from the factory. This plastic heat cycles from hot to cold to hot, then becomes brittle, and will eventually break over time. Broken impeller blades will prevent coolant from being cycled through your engine and lead to overheating. Also, the ball bearings on the pump are prone to failure over extended use as well.

Modern, electronic, water pumps may fail even sooner than mechanical, belt-driven pumps due to the less reliable electronics. Additionally, electrical water pumps are susceptible to the same types of failure as mechanical ones, bearings, and plastic impeller failure.

Upgrading to metal impeller blades.

Many aftermarket companies manufacture water pumps with metal impeller blades. These have a less likely chance of cracking and failing compared to plastic finned blades.

How often should I change my water pump?

It is recommended to change your water pump every 80,000 miles (129,000km). It is critical to replace wearable components BEFORE they fail, not AFTER they fail. Therefore, preventative maintenance is the largest factor in ensuring the longevity of your BMW. Follow your maintenance manual on your vehicle to avoid catastrophic damage. You may think you are saving money by waiting until a part fails, but once the part fails the ancillary damage caused will almost always outweigh the cost of replacing the part prior to failure.

The bottom line:

BMWs have a reputation around the car community for having weak coolant systems. The reality is, they are robust if you perform the proper maintenance. Many of these older BMW models are falling into the hands of younger owners who cannot afford to properly maintain them and complain every time failure occurs. The vehicle is not properly maintained as the original design intended. Above all, perform preventative maintenance and replace your water pump at the service intervals recommended to avoid engine overheating.

Where can I learn more BMW fun facts?

Learn more BIMMERtips fun facts by clicking HERE

	Acid Orange: C2T Made famous by the style 666 F80 M4 GTS wheels as the accent color found through the vehicle, including the wheels.
	Chrome Shadow Silver: A56 A difficult paint to match. A unique process in which the wheel is finished in black paint first then sprayed lightly with silver to allow some of the black to show through. Not many wheel sets from the factory matched exactly the same due to the unique finish process. Seen on Style 65 (E39 M5) and style 40 (Z3 M Coupe, S54) wheels.
	Decor Silver I: A55 Used for most M Sport wheels from the early 2000s such as the E46 M3 CSL style 127, E46 ZHP style 135, style 166, style 193 etc.
	Decor Silver II: B20 Used for most M Sport wheels from the 2010s such as the F10, F2X, F3X. Style 193, 261, 326, 361 etc
	Ferric Grey I: A80 A dark gray metallic color, not a full on black. Used for most M Sport wheels from the 2010s such as the F22 M235i. Style 436, 400 etc.
	Orbit Grey: B35 A dark gray metallic color, not a full on black. Used with modern M wheels, late 2010s.
	Silver: 144 The standard silver wheel color up to approximately 2006.

What is the difference between direct and port injection?

Direct injection sprays fuel directly into the cylinder head while port injection sprays the fuel into the intake ports. Reference the images below for further clarification on the location of the fuel injectors in the two setups.

What are the advantages and disadvantages of direct injection?

By spraying the fuel directly into the cylinder head, the air-fuel mixture is more controlled and a cleaner burn results in better emissions. Compared to port injection, direct injection uses high-pressure fuel injectors which atomize the fuel into smaller particles, mist, creating a more efficient burn. Fuel economy is this improved by as much as 10 - 15%. Direct fuel injectors spray fuel over 1,500 PSI compared to port fuel injectors at around 50 PSI. Furthermore, by injecting the fuel directly into the cylinder head, the fuel helps reduce the cylinder head temperatures resulting it wasted energy in the form of heat.

The disadvantages of direct injection are that the injectors are much more expensive than traditional port injectors. Because the fuel flow is highly controlled the fuel flow rate is critical and must be calibrated to a higher degree of tolerance. Because of this high-pressure requirement, higher pressure fuel pumps are also required, thus, further increasing cost.

Due to the extreme heat produced in the cylinder head, the injectors are required to be manufactured from materials able to withstand this high heat and still function. As a result, the cost of each injector further increases when compared to port injectors.

Carbon buildup can occur on the intake valves. Due to the fuel being injected after the air passes over the valves, the fuel no longer acts as a cleaning agent to the valves. Direct injection engines will see carbon buildup on the valves as a result, decreasing fuel flow efficiency and performance. Further symptoms of carbon buildup on the valves may result in engine misfires and rough idle. This carbon buildup will require walnut blasting for removal, further increasing the cost of ownership over time.

Direct Injection Advantages

➊ Increased fuel efficiency
➋ Increased performance
➌ Decreased emissions

Direct Injection Disadvantages

➊ Higher cost of ownership over time
➋ Carbon buildup on the intake valves
➌ Potential for misfires, rough idle

What was the first BMW engine to use direct injection?

The first turbo engine to use direct injection was the N54 (2006 - 2016), the first naturally aspirated engine to use direct injection was the N53 (2006 - 2013, not sold in the USA). Since all modern BMW models are turbocharged, all current models feature direct injection.

Since the N53 was the first direct injection naturally aspirated motor, this makes the N52 the last port-injected motor BMW offered, 2004 - 2015.

How can I prevent buildup in my fuel lines and injectors?

Fuel system maintenance is often overlooked while maintaining a car. Replacing your fuel filters while keeping your fuel lines, fuel injectors and valves clean are a must. Maintaining a properly clean fuel system will ensure longevity of the fuel components as well as ensure performance.

There are a lot of options on the market for fuel system cleaners, however, we only suggest one product which trumps them all. Liqui Moly fuel system cleaner. 100% safe for direct or port injection fuel systems. Made In Germany.

This additive contains a highly effective combination of cleaning and treatment for all gasoline injection systems such as K, KE, L-Jetronic and similar systems. Removes deposits on injection valves, intake valves, spark plugs and in the combustion chamber and prevents them from reforming. Improves engine running and optimizes the exhaust gas values. Eliminates start problems and rough engine running. Maintains and protects the entire fuel system from wear, deposits and corrosion. Clean engines need less fuel and reduce emissions.

Where can I buy Liqui Moly Fuel System Cleaner?

BUY NOW by clicking HERE

BMW rod bearings have tarnished the legacy of the M brand due to premature failure. Learn about the details of how the failure occurs and how to prevent it.

What are engine rod bearings?

Connecting rods are what connects the piston to the crankshaft. The connecting rod moves the piston up and down as the crankshaft rotates. The connecting rod features inserts called rod bearings (more specifically “split sleeve bearings” which reduce the friction with the crankshaft.

Split sleeve bearings feature stacked layers of different metals which, when lubricated, provide a smooth surface for the connecting rod to rotate on about the camshaft. The split sleeve bearings do not feature ball bearings as one may assume. This is due to the extreme stresses and heat generated which would fail a traditional ball bearing setup. Insufficient lubrication will result in the two metals touching and ultimately lead to engine failure.

Reference the image below to see what worn rod bearings look like with insufficient oil supply.

What BMW engines are most prone to rod bearing failure?

S54 (inline 6), S65 (V8), S85 (V10)

Why do BMW rod bearings fail?

The high revving nature of the S54, S65, and S85 engines require exceptionally tight tolerances between parts for the engine to perform optimally. The clearance gap between the crankshaft journals and connecting rod bearings is approximately .001 inches (.025mm). This gap makes it difficult for oil to travel between the two surfaces to provide sufficient lubrication, especially when the incorrect oil is used.

Factors that contribute to failure:

Using inferior oil. Phosphorus works together with Zinc to form a protective layer on surfaces when in extreme heat and pressure environments. This is ideal for rod bearings. The additives of Zinc and Phosphorus in oil is called ZDDP or Zinc Dialkyldithiophosphates which was common in older oils.

Upon original delivery, BMW used Castrol 10w-60 oil in its engines which featured the ZDDP additive, however, the oil has since been modified to meet the demands of newer emission standards. The downside of using phosphorus in oil is the carbon build-up which it produces. Carbon build-up will decrease the life of catalytic converters and oxygen sensors. Since the mid-1990s, the use of phosphorus in engine oil has been slowly phasing out to increase the life of catalytic converters.

Poor oil maintenance. Because the original maintenance schedule of these older cars assumed the use of ZDDP found in the oil, BMW recommended oil changes every 15,000 miles. Because modern oils do not feature the same levels of ZDDP, going 15,000 miles between changes can cause premature failure to the rod bearings.

Changing your oil at shorter intervals will ensure proper lubrication of the rod bearings between oil changes. For daily driven vehicles, it is recommended 10,000 miles between changes and 5,000 miles between changes for high RPM driving.

How often should rod bearings be replaced?

It is recommended to change the S54, S65, and S85 rod bearings every 60,000 - 80,000 miles. Replacing the rod bearings will allow for aftermarket bearings and connecting rod bolts to be fitted, providing more clearance than factory to sufficiently lubricate the parts. This work should be performed reputable shop as the work is highly specialized. Specific torque sequences are necessary to ensure the rod bearings deform properly to the crankshaft. Because oil properties are constantly changing, we recommend calling a local BMW performance shop to get the latest guidance on oil choice.

Where can I learn more information on oil weights and viscosity?

Learn more BIMMERtips information on oil by clicking HERE