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Tips for Manual Petrol Car Drivers
This is the most common car type on UK roads today, although diesel cars with a manual gearbox will probably take the lead in the near future, still with me? It’s worth mentioning that in this type of car, with the exception of steep hills, you should never need to go over 3000rpm. Tearing up the gears, then cruising in 5th gear, is NOT driving for economy! I have tested all the fuel economy myths, the old method of the lowest revs in the highest gear, works quite well, (eg: 1500rpm in 5th gear) but there are other factors that you must be aware of. A method I like to employ, is what I call the Imaginary Rev Limit, where for instance on a flat road, starting from a standstill, you imagine that you can’t exceed 2000rpm but there is a rule you must apply to this method, and it is just simply, never let the engine struggle. If you are sitting at 1500rpm in 5th gear, and the car is chugging, or vibrating badly, then you have two options. Option 1: Increase your speed in 5th gear, until the car runs smoothly again. Option 2: Drop down to 4th gear to lessen the strain on the engine. Whatever option you choose, the engine would no longer be stressed. Option 1, would yield the highest fuel economy on a flat road, or a slight uphill stretch. This method does not take the engine ‘Sweet Spot’ into account, but it will serve you well if you can’t find the sweet spot. There was a time in the past when even I believed the sweet spot was a myth, but it is there, you will find it somewhere between 40-60mph in 5th gear (or 6th if you have a 6 speed box), in difficulty to find it’s similar to the G-Spot in women! If you have a mpg computer in your car, which gives an accurate reading in real time (a lot of them don’t), you should be able to see it, by varying your speed while cruising in your highest available gear. If you have a spare £100, you could buy a scangauge, you can find them on the internet, just google the name, it plugs into the OBD Socket found under the dash in most cars. It is much more than an mpg meter, and is extremely accurate, but probably only justifiable for a serious fuel economy nut like me. To sum up the sweet spot, I think it is accurate to say that it is a product of the torque characteristics of your engine, and is usually found at the peak point in the rev range where torque delivery is at its strongest, which is why it varies from car to car. Read the article ‘Driving Style’ for a snippet of knowledge on how to keep your engine running without using any fuel. What did he just say? Alright it was a little play on words, but the point I would like to get across, is that there are times when your car is using no fuel at all, and you can exploit that knowledge if you know when it’s happening.
