Question: I recently purchased a new 2016 CRV Honda — four cylinder — and found out it comes with synthetic oil in the engine. I have always had regular oil in all my cars and would like to know which is better or should I switch back to regular oil at my first oil change. I would like to know the pros and cons for the use of synthetic oil and are there different grades like regular oil?
Answer: While they may not advertise it, most new vehicles come from the factory with synthetic engine oil. Although there are different viscosity synthetic oils, just like there are different viscosity conventional oils, many of the vehicles come with 0W-20 synthetic oil and this is specified as the replacement oil.
The big disadvantage of synthetic oil is the increased cost, although the advantages offset this. Synthetic oils flow easier at very cold temperatures so during a cold weather engine start, the oil gets to the moving parts faster to provide lubrication and this reduces engine wear. The colder the weather, the bigger the advantage this is.
Synthetic oil also provides better lubrication in extreme heat conditions. Conventional oils will tend to thin as they get hotter while synthetic oils retain viscosity better. The hotter the weather or the more load on the vehicle, the more advantage the synthetic oil will provide.
The reason many vehicles now come equipped with 0W-20 oil is it flows easier in all weather conditions due to the low viscosity. This reduces friction losses in the engine and lowers the power needed to pump the oil through the engine. It may be small, but it adds up to provide increased fuel economy compared to a higher viscosity oil.
You can switch to conventional oils, preferably at an oil change, but the cost of oil is only a small part of total vehicle operating costs. I would stay with the synthetic oil, especially if you have cold starts in winter and drive extensively on the highway on hot summer days.
Question: I have a 2007 Chevrolet Avalanche LTZ with the Autoride suspension and the dash occasionally shows a message to check suspension. I can clear the message but it returns usually in a day or two.
I took the truck to my dealer and he tells me that one of the rear shock absorbers is bad and causing the problem message. Also, he let me know that to replace the rear shocks would be nearly $1,800. I have looked on the Internet and there are many new shocks for sale for only a couple hundred dollars, but they are not for the Autoride suspension. I also see some replacement units for Autoride that are a little more expensive and they have a module that keeps the warning message from appearing. What do you think my best choice would be?
Answer: The Autoride suspension on your Avalanche uses shock absorbers that have variable rate damping. An electrical connector on the shock absorber body operates a solenoid inside the shock to change the damping rates — softer for a smooth ride or firmer when the roads get bumpy. In addition, the rear shock absorbers on the LTZ model include integrated air bags for the automatic level control to compensate for loads. Those two features make the original equipment rear shock absorbers quite expensive.
You could replace the shocks with conventional shocks but you would be doing away with the Autoride and auto level features. In addition, the check suspension warning message would continually appear on the dash information display. A better choice would be units that include the air bag so the auto leveling is retained and have a module that keeps the warning message off. You would no longer have Autoride suspension.
The module is a simple resistor plugged into the wiring. When the vehicle is started, the Autoride module checks the resistance of the electrical circuit to all the shocks, and if one is incorrect, it turns on the warning message. By plugging in the correct resistance, you are fooling the Autoride module so that it thinks all the shocks are correct.
Personally, I like the Autoride suspension ride comfort and handling so I would prefer to go with original equipment type shock absorbers, but you may feel it is not worth the additional cost.