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General Banter / The great diesel con...
« on: November 18, 2011, 07:47:25 pm »
Jeep UK are only offering model year 2012 Wranglers with diesel engines and auto boxes. I figured this made good sense, despite the 2.8 being long in tooth and the new Pentastar v6 petrol being a really nice unit. I mean, Jeeps use a lot of fuel, you get so much more mpg out of diesel, you'd be mad to buy a petrol Jeep right?
Wrangler Sahara 4 dr Auto 3.6 V6
Combined 24.1 mpg
Extra Urban 30.7 mpg
Urban 17 mpg
0-62 8.9 sec
top speed 112mph
Wrangler Sahara 4 dr Auto 2.8 CRD
Combined 34.0 mpg
Extra Urban 38.7 mpg
Urban 28.2 mpg
0-62 10.7 sec
top speed 107mph
Time for some maths!
So on the Sahara, ie like for like, the diesel gets 26% better mpg on the long extra urban run, a whopping 66% better fuel economy around town but overall 41% improvement in mpg in general.
Diesel is clearly the way forward, surely!?
The cheapest petrol near me is 128.9.
Assuming 1,000 miles per month on the combined cycle the Pentastar would cost:
1 month - £243.14
1 year - £2,917.68
3 years - £8,753.04
5 years - £14,588.40
The cheapest diesel near me is 136.9
Assuming 1,000 miles per month on the combined cycle the diesel would cost:
1 month - £183.04
1 year - £2,196.48
3 years - £6,589.44.
5 years - £10,982.40
So over 5 years and 60,000 miles I would save £3,606 by running the diesel.
I don't know what the difference in tax would do to that figure, I assuming the diesel is cheaper on tax but still in a high bracket but probably a good couple of hundred quid a year to save there.
I'm not sure what the price difference between the 2 engines is as I guess officially we only get the diesel over here which makes a fair comparison difficult...
But typically diesels cost a good £1,000 or even £1,500 more than petrol equivalents right? If so it looks like running a diesel saves you less than £3,000 over 5 years even allowing for the £300 per year tax saving...
Now, just for kicks imagine we LPG the Pentastar and lose 15% fuel economy in doing so...
The cheapest LPG near me is 70.9
1 month - £157.23
1 year - £1,886.76
3 years - £5,660.28
5 years - £9,433,80
This means that over 5 years the Pentastar on LPG becomes £1,500 cheaper to run than the diesel, or even £2,500 - £3,000 cheaper than the diesel if we assume the Pentastar is that much cheaper to buy as we have said.
But then we need to take £2,000 off that saving for the cost of the LPG conversion in the first place. So a Pentastar on LPG would be between £500 and £1,000 cheaper than a diesel over 5 years...
I may have to rethink my opinion on diesel being the only real engine option.
Even if you use the Jeep daily and do decent mileage over 5 years the savings don't really add up to that much (I know £2,500 is still £2,500) really?
And if LPGing the Pentastar is viable then it would be the cheapest total cost of ownership, and be faster and frankly much nicer to drive and less of a health hazard!
Did you ever think we were being conned into diesels?!?!
Wrangler Sahara 4 dr Auto 3.6 V6
Combined 24.1 mpg
Extra Urban 30.7 mpg
Urban 17 mpg
0-62 8.9 sec
top speed 112mph
Wrangler Sahara 4 dr Auto 2.8 CRD
Combined 34.0 mpg
Extra Urban 38.7 mpg
Urban 28.2 mpg
0-62 10.7 sec
top speed 107mph
Time for some maths!
So on the Sahara, ie like for like, the diesel gets 26% better mpg on the long extra urban run, a whopping 66% better fuel economy around town but overall 41% improvement in mpg in general.
Diesel is clearly the way forward, surely!?
The cheapest petrol near me is 128.9.
Assuming 1,000 miles per month on the combined cycle the Pentastar would cost:
1 month - £243.14
1 year - £2,917.68
3 years - £8,753.04
5 years - £14,588.40
The cheapest diesel near me is 136.9
Assuming 1,000 miles per month on the combined cycle the diesel would cost:
1 month - £183.04
1 year - £2,196.48
3 years - £6,589.44.
5 years - £10,982.40
So over 5 years and 60,000 miles I would save £3,606 by running the diesel.
I don't know what the difference in tax would do to that figure, I assuming the diesel is cheaper on tax but still in a high bracket but probably a good couple of hundred quid a year to save there.
I'm not sure what the price difference between the 2 engines is as I guess officially we only get the diesel over here which makes a fair comparison difficult...
But typically diesels cost a good £1,000 or even £1,500 more than petrol equivalents right? If so it looks like running a diesel saves you less than £3,000 over 5 years even allowing for the £300 per year tax saving...
Now, just for kicks imagine we LPG the Pentastar and lose 15% fuel economy in doing so...
The cheapest LPG near me is 70.9
1 month - £157.23
1 year - £1,886.76
3 years - £5,660.28
5 years - £9,433,80
This means that over 5 years the Pentastar on LPG becomes £1,500 cheaper to run than the diesel, or even £2,500 - £3,000 cheaper than the diesel if we assume the Pentastar is that much cheaper to buy as we have said.
But then we need to take £2,000 off that saving for the cost of the LPG conversion in the first place. So a Pentastar on LPG would be between £500 and £1,000 cheaper than a diesel over 5 years...
I may have to rethink my opinion on diesel being the only real engine option.
Even if you use the Jeep daily and do decent mileage over 5 years the savings don't really add up to that much (I know £2,500 is still £2,500) really?
And if LPGing the Pentastar is viable then it would be the cheapest total cost of ownership, and be faster and frankly much nicer to drive and less of a health hazard!
Did you ever think we were being conned into diesels?!?!