More car questions for those who will share opinions...??

[DandyDon]

I don't think I want my old mechanic's opinion on this 2007 Impala I bought last year. He's good on older vehicles, but not keeping up - and I haven't needed a new one yet. So give me some opinions please...

(1) So how often do you change oil...?

I know the old 3,000 miles or 3 months suggestion has to be wasteful, of more benefit to those in the business, but can I really go with my onboard computer suggestions? After 4 months and 3700 miles is says I have 58% left. At this rate, 8 months & 7500 miles will still be under limit, and I am a boring driver - slow on the take off, max speed usually 60 mph to save on gas, coasting into stops, and don't get off the pavement much.


(2) So what do you think of fuel additives for injector cleaners...?

My old '95 F-150's check engine light stayed on after 200K miles or so, and my old mechanic suggested a few bottles of that - and it worked! After it cleared up, I stuck a bottle in every oil change, and I didn't do those too often on it either - but it ran ok to over 300K. The gas I'm getting now is 10% ethanol of course, and I saw on the pump today that they claim their's has plenty of detergent - cautioning against over treating. Damn, who do you believe...??


(3) While we're talking, I have a problem with an electronic tire sensor...

I have one tire that reads several pounds lower than with a manual guage, and I tried 2 more new guages today. Hehe the digital guage was set on Bars, threw me for a minute until I changed it. The salesman was very nice, but he didn't know about that one.

Thanks in advance for your varied opinions. Hope to get a few here...

 

[Dr. Lecter]

Re: (1), I took care of my old British car by changing the oil every 5-10k (it was a V12 and ate a full case of 20W50 per change) but swapping oil filters every 1,500 miles. The oil doesn't break down nearly as fast as it accumulates wear material that will eventually start bypassing a full filter.

 

[tplyons]

I change my oil every 5,000 miles or so. Modern oil is much better than what it used to be. New filter every time but I haven't seen a need to change filters more often.

Fuel additives? Never used them. Not in my old El Camino with 200k miles that ran like a dream or my more modern Chevy HHR. I've always used good quality fuel though, and have never had an issue.

Tire Pressure Sensors? You're on your own. Never had a car with them.

 

[DandyDon]

I've considered changing filters between changes, or DIY changes between full services changes - but I'm not.

Tire Pressure Sensors? You're on your own. Never had a car with them.

Your Chevy HHR doesn't come under this...?

In the United States, the United States Department Of Transportation (NHTSA) released the FMVSS No. 138, which requires an installation of a Tire Pressure Monitoring System to all new passenger cars, multipurpose passenger vehicles, trucks, and buses that have a gross vehicle weight rating (GVWR) of 4,536 kg (10,000 lbs.) or less, except those vehicles with dual wheels on an axle, as of 2007.

 

[smellzlikefish]

In the United States, the United States Department Of Transportation (NHTSA) released the FMVSS No. 138, which requires an installation of a Tire Pressure Monitoring System to all new passenger cars, multipurpose passenger vehicles, trucks, and buses that have a gross vehicle weight rating (GVWR) of 4,536 kg (10,000 lbs.) or less, except those vehicles with dual wheels on an axle, as of 2007.

That's an example of a law written by bureaucrats with too much time on their hands. Why can't cars just be four wheels, seat, and a steering wheel? I much prefer simple cars with roll up windows, manual door locks and manual transmissions. I believe in the UK they would call this a nanny state.

 

[Doubler]

I just bought a brand new Toyota Highlander and it does not have a tire pressure monitoring system.

I change oil every 5000 miles or 6 months

 

[DandyDon]

I just bought a brand new Toyota Highlander and it does not have a tire pressure monitoring system.

I change oil every 5000 miles or 6 months

I wonder why you don't have TPMS [-]or why your post doesn't have a Like link.[/-] Wait there it is.

That's an example of a law written by bureaucrats with too much time on their hands. Why can't cars just be four wheels, seat, and a steering wheel? I much prefer simple cars with roll up windows, manual door locks and manual transmissions. I believe in the UK they would call this a nanny state.

Well, you're a lot of help...!

In the European Union, starting November 1, 2012, all new models of passenger cars must be equipped with a TPMS, with even tighter specifications that will be defined by the UNECE Vehicle Regulations (Regulation No. 64).

 

[mrfixitchapman]

So. Before I get into oil life monitors I'll tell you the back story on Tire Pressure Monitor Systems. Set your WayBack Machine to the year 2000. Remember that Ford Explorers were bursting tires, rolling over and killing people? Well, your Congress decided to Solve The Problem. The actual problem was not Ford Explorers or the Firestone tires. The problem was that people were driving around on dangerously underinflated tires. The tires overheated, delaminated and fell apart. The Ford Explorer happened to be the most popular vehicle sold at the time, and they happened to arrive with Firestone tires. Since drivers could not be trusted to maintain tire pressure, Congress made it A Law. Two types of tire pressure monitoring strategies were used. Indirect pressure monitoring used the individual wheel speed sensors that the antilock brakes use. If two wheels on the same axle are turning at different speeds it was assumed that the reason had to be that the tire with less air in it had to make more revolutions per mile than the correctly inflated tire. Sometimes that system works, but it did not require that each tire have an actual pressure sensor. Later systems required individual tire pressure sensors. Tire pressure sensors are famous for failure. The GM sensors should be replaced as a set, not individually. The new upgraded sensors have a rubber stem instead of the metal stem with a threaded nut and washer. Much more reliable. Do The Google Thing for technical service bulletins. Some are covered, some are not. Every GM service manager is used to answering unhappy cutomers' calls. There are also aftermarket TPMS pressure sensors, my favorite is the VDO replacement set. They are reliable and affordable. P.S. Sometimes the TPMS pressure sensors quit when the tiny little batteries lose their itty-bitty voltages. Too bad, replace the sensor. Batteries not serviceable separately.

Now. About the Oil Life Monitor system. Trust it. GM has been using some version of this system since the early 90's. The software assumes that new oil will be good enough, ( pay attention to the replacement oil, the GM DEXOS oil is a very high specification synthetic), and the engine is filled full enough. After that the software assigns 'penalty miles' for sustained high speed use, hard acceleration, sustained idling, towing, short trips, high temperature, low temperatures, everything that causes oil to wear out too soon. If you drive your car inside the parameters the oil life monitor will reward you with long oil change intervals. It works just fine, the bugs are all worked out of the system. Three notes, A. If you don't trust the system you can change the oil more often, B. We have sent oil samples in to testing labs for some of our fleet vehicles and found no unusual results at 7500 mile intervals. And C. Check your oil level occasionally. If your engine only burns a quart of oil every 5000 miles, you can be down more than a quart between changes. Bad thing.

Some fun, eh?

DC

 

[DandyDon]

Thanks for the info MrFix!

So I think I will start using my hand guage more. I need to read up and see if I have Direct or Indirect tho. Oh, I don't check fluids weekly, but maybe monthly. And I think I will roll on to 7500 miles and call it then even if the computer says I have more left.

Surely you have an opinion about fuel additives, like injector clearner every oil change...??

 

[Dr. Lecter]

After that the software assigns 'penalty miles' for sustained high speed use, hard acceleration, sustained idling, towing, short trips, high temperature, low temperatures, everything that causes oil to wear out too soon.

Sounds like a decompression algorithm. Do we adjust the conservatism setting, or is this a gradient factors system?