| Yes, 车冷胎压和热胎压要差很大, about 5 PSI |
2009-01-29 14:28:11 |
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The nominal psi labelled on tires or car doors referred to cold. You should pump up the tires when the car has not been driven for at least 1 hour in winter (in summer it could be much longer); basically it means when tire temperature is the same of that in ambience, ideally in early morning.
By the way, be aware of the following factors:
(1) Always check max PSI for each tire before pumping. Some times tires may be changed due to flat or other causes.
(2) For most all season radial tires, car manual and car door recommend 29-35 psi tire pressure, that is a compromise of gas mileage, comfortability, tire longivity and risk factors. However, per individual preferences, the number can be changed - if you want to have better gas mileage, you can set the pressure higher; if you drive on highway a lot, the pressure can be higher; if you are driving on muddy road, you shouldn't over pumpped. The bottom line is - never put the tire pressure above the TIRE MAX psi allowed.
My tires are max 51 psi and I am driving in sunny SoCal, and on highways a lot, so I normally pump my tires to 42 psi.
(2) Check tire pressure often - believe it or not, the pressure can be lost quite fast. You should check tire pressure every two weeks, or once a month as the longest. The low tire pressure really kills your gas mileage.
(3) Buy an electric pump, it pays itself - the gas you saved will offset the cost of the pump. In Harbor Freight, there is a good one around $20 on sale, large volume which means quicker pump-up, very solid design. |
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| When DIY, recommend to use quality oil |
2009-01-29 12:39:51 |
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Oil is one of most important consumbles during the entire life of a car.
One can save money by driving a car without CD changer, no sunroof, but don't save money on oil - it directly affects the longivity of engine. My recommendations are:
(1) Follow user manual. If it specifies the type of oil to be used, make every effort to get it, even though that means some times you might need to spend more money.
(2) If no specification of oil on the manual, buy quality oil, like Castrol, etc.
(3) Pay attention to the oil numbers - they really mean something. For example, for diesel engine, if no specific requirement, use 15w40, for gas engine use 5w30 (newer cars), or 10w30, and so on.
This post is intended for the newbies; FYR only.
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| Mission accomplished - changed motor mounts |
2009-01-18 14:18:21 |
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Since 3 months ago I have had a feeling that my 300SDL engine mounts must be dead because a striking sound could be heard when driving on the road in low rpm. One time I tried to loose the mounts so to see how bad they were, and found one of allen bolts was stripped, I knew it might be hard to take it out.
This weekend is a long one, so I thought it might be a good time to do it - in case I need parts, if general parts stores don't carry them, at least I can go get them from dealer on Monday. On Friday, I called around trying to find the OE mounts made by Lemforder, but no avail except dealer quoted me $138 for two, and it's a special order, taking 2 days to get here. I was thinking oh well I can't do it this weekend anyway...
Yesterday morning I searched online and found a German parts importer in Delaware who carries the brand. I called them to see if I can buy from them, luckily they were open on Saturday but the rep told me they are whole sellers and only sell parts to stores or shops not individual. But he said I could order through Carquest.
Carquest is the last store I'll ever go to among all national parts stores whenever I need parts, but this time looks like I had no other options. I called them and they said yes they could order it for me, $48 for two and they could get them in store at 2 pm. I ordered right away and went to pick them up later on the day.
On my way back I went to Sears to buy a bolt extractor (note: Sears carries Craftsman, one of the best quality tools in US. I always buy tools with this brand, even though it's more expensive than Autozone or alike's, but I can be sure that I won't get my hands hurt when work on cars).
This morning, starting at 9, it was a smooth process - jacked up car, loosed large bolts, jacked up engine, took retaining bolts out (thanks for the extractor, no effort), and lada lada... all done before 12:00.
I just had a road spin, it was a smooth ride; it backed to where it should be. Mission accomplished!!
Phew...
(Engine mounts require special rubber to make. According to many other members at benzworld.org where I am a member too, all after market mounts won't last long. The only reason not to use OE is if you really enjoy changing motor mounts...)
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| 回复：问一个WINDSHIELD WASHER TANK 的问题 |
2009-01-12 13:34:51 |
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At the bottom of windshield fluid reservoir, there is a pump with a hose coming out leading to a Y spliter where two hoses connecting to nuzzles. Premium cars have a level sensor normally affixed to the top of the reservoir.
I am not sure how old your car is and what make/model is. I tend to believe that it's very rare they would touch the bottom hose to do regular services; rather, they would check the level from top and fill it up to the proper level if it's low. AND, noramlly a reputable shop or dealers won't do small tricks attempting to make couple of ten dollars by risking their reputations - they are in business, their reputation is more important than a small amount of quick money.
It might just be a coincident on the timing, or unknowingly they made the bottom hose loose. If doublt, don't go to the same dealer for future services.
** By the way, windshield fluid is very cheap from parts stores, less than $2/gallon. Don't add just "water" into it as you did. |
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| General speaking, brake fluid should be changed every 30-40 kmi |
2009-01-03 15:01:03 |
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Re: 刹车油应该多少迈换呀？有什么办法检查该不该换呢？
General speaking, brake fluid should be changed every 30-40kmi. If you don't do it, you won't see much problem, however, something you should know:
1) Brake fluid has the charactor of absorbing moisture from air. Overtime, your brake fluid will contain certain percentage of water; consequently, the braking efficiencty will be lower - when you run on the road/applying braking, the brakes are very hot and water becomes evaporized, you are having air in the system. You'll feel the brake pedal being softer, requiring brake pedal travelling longer distance for you to stop; some times this could lead to a safety issue.
2) Because of water, when the brake pistons are supposed to be fully back to base but they won't, continuing to apply pressure to rotors, that is "dragging", you'll lose gas mileage at the least.
Chaning brake fluid involves "bleeding". If you know how to do it, it's fairly simple, but need two persons to do it; or you can go parts stores to buy a vacuum bleader, so one person can do it.
I always do it myself so I don't know how much shops charge (per car brand, model and conditions). |
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